I have heard/read somewhere that there were 8 major wives of Lord Krishna. Also there were some approx. 16,000 girls that Lord Krishna freed from Narakasura and as no one would marry them, therefore Lord Krishna married them all. However, out of the 8 major wives, I currently know of only Rukmini, Satyabhama and Jambavati and their stories. Can someone please tell me who the other ones are out of the 8 major ones? Also, please let me know their stories related to how they got married to Lord Krishna.
Let me discuss how Krishna married each of his Ashtabharya (eight queens):
Rukmini - She was the incarnation of Lakshmi and the daughter of Bhishmaka king of Vidarbha. As I discuss in this answer, Rukmini heard about Krishna's great qualities and wanted to marry him, but her brother Rukmi made arrangements for her to marry Krishna's enemy Shishupala. So as described in this chapter of the Srimad Bhagavatam, Rukmini sent a message to Krishna asking him to " kidnap" her:
O beauty of the worlds, having heard of Your qualities, which enter the ears of those who hear and remove their bodily distress, and having also heard of Your beauty, which fulfills all the visual desires of those who see, I have fixed my shameless mind upon You, O Kṛṣṇa. O Mukunda, You are equal only to Yourself in lineage, character, beauty, knowledge, youthfulness, wealth and influence. O lion among men, You delight the minds of all mankind. What aristocratic, sober-minded and marriageable girl of a good family would not choose You as her husband when the proper time has come? Therefore, my dear Lord, I have chosen You as my husband, and I surrender myself to You. Please come swiftly, O almighty one, and make me Your wife. My dear lotus-eyed Lord, let Śiśupāla never touch the hero’s portion like a jackal stealing the property of a lion.... O unconquerable one, tomorrow when my marriage ceremony is about to begin, You should arrive unseen in Vidarbha and surround Yourself with the leaders of Your army. Then crush the forces of Caidya and Magadhendra and marry me in the Rākṣasa style, winning me with Your valor. Since I will be staying within the inner chambers of the palace, You may wonder, “How can I carry you away without killing some of your relatives?” But I shall tell You a way.... If I cannot obtain Your mercy, I shall simply give up my vital force
A Rakshasa marriage is a type of marriage I discuss here, by the way. In any case, Krishna went to Vidarbha, rescued Rukmini, and defeated the forces of Rukmini's brother Rukmi. They then went back to Dwaraka, where Krishna and Rukmini got married, as described in this chapter of the Srimad Bhagavatam. Their eldest son was Pradyumna, whose son was Aniruddha, whose son was Vajra. It was Vajra who became king of the Yadavas after the massacre of the Yadavas and Krishna's departure from the Earth, which I discuss here.
Jambavati - She was the daughter of Jambavan, the bear who helped Rama during the Ramayana, and whom Rama blessed with long life as I discuss here. There was once a Yadava living in Dwaraka named Satrajit, whom I discuss in this question. Satrajit was a great devotee of Surya the sun god, so Surya gave his the famous Syamantaka gem, which bestows wealth on whoever wears it. Krishna advised Satrajit to give it to Ugrasena, king of Dwaraka, but Satrajit refused. Then the Syamantaka gem went missing, and Satrajit accused Krishna of stealing it. To clear his name, Krishna tracked down the gem to the mountain cave of Jambavan, who had found the gem but had given it to his son to play with. So Krishna fought Jamabavan to get the gem back. Jamabavan realized that Krishna was an incarnation of Vishnu, and thus a rebirth of Rama whom Jamabavan had the utmost loyalty to So he gave Krishna the Syamantaka gem, and he also gave him his daughter Jambavati's hand in marriage, as described in this chapter of the Srimad Bhagavatam:
Lord Kṛṣṇa then addressed the king of the bears, who had understood the truth. The lotus-eyed Personality of Godhead, the son of Devakī, touched Jāmbavān with His hand, which bestows all blessings, and spoke to His devotee with sublime compassion, His grave voice deeply resounding like a cloud. "It is for this jewel, O lord of the bears, that we have come to your cave. I intend to use the jewel to disprove the false accusations against Me." Thus addressed, Jāmbavān happily honored Lord Kṛṣṇa by offering Him his maiden daughter, Jāmbavatī, together with the jewel.
By the way, Krishna and Jambavati had a son named Samba, who was responsible for the destruction of the Yadava race as I discuss here.
Satyabhama - She was the incarnation of Bhumidevi goddess of the Earth and daughter of the Yadava Satrajit I discuss above. When Krishna came back to Dwaraka upon marrying Jambavati, he returned the Syamantaka gem to Satrajit. Satrajit felt guilty that he had falsely accused Krishna, so he gave Krishna his daughter Satyabhama's hand in marriage, as described in this chapter of the Srimad Bhagavatam:
Pondering over his grievous offense and worried about the possibility of conflict with the Lord’s mighty devotees, King Satrājit thought, “How can I cleanse myself of my contamination, and how may Lord Acyuta become satisfied with me? What can I do to regain my good fortune and avoid being cursed by the populace for being so short-sighted, miserly, foolish and avaricious? I shall give my daughter, the jewel of all women, to the Lord, together with the Syamantaka jewel. That, indeed, is the only proper way to pacify Him.” Having thus intelligently made up his mind, King Satrājit personally arranged to present Lord Kṛṣṇa with his fair daughter and the Syamantaka jewel. The Lord married Satyabhāmā in proper religious fashion. Possessed of excellent behavior, along with beauty, broad-mindedness and all other good qualities, she had been sought by many men.
Krishna refused the Syamantaka gem, by the way. But ultimately Satrajit was murdered by the gem by fellow Yadavas.
Kalindi - She is the goddess of the Yamuna river, and daughter of Surya the sun god as I discuss here. Once Krishna and Arjuna went hunting on the banks of the Yamuna river, when they came across a beautiful woman. This chapter of the Srimad Bhagavatam describes what happened next:
The great warriors then saw an attractive young girl walking nearby. Sent by his friend, Arjuna approached the exceptional young woman, who possessed beautiful hips, fine teeth and a lovely face, and inquired from her as follows: "Who are you, O fine-waisted lady? Whose daughter are you, and where do you come from? What are you doing here? I think you must be looking for a husband. Please explain everything, O beautiful one." Śrī Kālindī said: "I am the daughter of the sun-god. I desire to get as my husband the most excellent and munificent Lord Viṣṇu, and to that end I am performing severe penances. I will accept no husband other than Him, the abode of the goddess of fortune. May that Mukunda, the Supreme Personality, the shelter of the helpless, be pleased with me. I am known as Kālindī, and I live in a mansion my father built for me within the water of the Yamunā. There I will stay until I meet Lord Acyuta." ...
Then Lord Kṛṣṇa, given leave by Arjuna and other well-wishing relatives and friends, returned to Dvārakā with Sātyaki and the rest of His entourage. The supremely auspicious Lord then married Kālindī on a day when the season, the lunar asterism and the configurations of the sun and other heavenly bodies were all propitious. In this way He brought the greatest pleasure to His devotees.
Mitravinda - She was the princess of Avanti and daughter of Vasudeva's sister Rajadhidevi. Mitravinda was attracted to Krishna but her brothers objected to the marriage because they were allies of Duryodhana. So Krishna kidnapped Mitravinda from her Swayamvara, as described in this chapter of the Srimad Bhagavatam:
Vindya and Anuvindya, who shared the throne of Avantī, were followers of Duryodhana’s. When the time came for their sister [Mitravindā] to select her husband in the svayaṁvara ceremony, they forbade her to choose Kṛṣṇa, although she was attracted to Him. My dear King, Lord Kṛṣṇa forcibly took away Princess Mitravindā, the daughter of His aunt Rājādhidevī, before the eyes of the rival kings.
Satya - Also known as Nagnajiti, she was the daughter of Nagnajit king of Ayodhya, not to be confused with Shakuni's uncle Nagnajit whom I discuss here. Krishna went to Ayodhya to attend Satya's Swayamvara. Satya was eager to marry Krishna and Nagnajit was eager to have him as a son-in-law, but Nagnajit had previously imposed the requirement that suitors would have to subdue his seven ferocious bulls. Krishna defeated them easily and then married Satya, as described in this chapter of the Srimad Bhagavatam:
Upon hearing these terms, the Lord tightened His clothing, expanded Himself into seven forms and easily subdued the bulls. Lord Śauri tied up the bulls, whose pride and strength were now broken, and pulled them with ropes just as a child playfully pulls wooden toy bulls. Then King Nagnajit, pleased and astonished, presented his daughter to Lord Kṛṣṇa. The Supreme Personality of Godhead accepted this suitable bride in the proper Vedic fashion. The King’s wives felt the greatest ecstasy upon attaining Lord Kṛṣṇa as the dear husband of the royal princess, and a mood of great festivity arose. Conchshells, horns and drums resounded, along with vocal and instrumental music and the sounds of brāhmaṇas, invoking blessings. The joyful men and women adorned themselves with fine clothing and garlands.
Then with with the help of Arjuna, Krishna fought off the rival suitors who tried to stop him.
Bhadra - She was the princess of Kaikeya and daughter of Vasudeva's sister Shrutakirti. Krishna was voluntarily given Bhadra's hand in marriage by her brothers, as described in this chapter of the Srimad Bhagavatam:
Bhadrā was a princess of the Kaikeya kingdom and the daughter of Lord Kṛṣṇa’s paternal aunt Śrutakīrti. The Lord married Bhadrā when her brothers, headed by Santardana, offered her to Him.
Lakshmana - She was the princess of Madra, and she was kidnapped by Krishna, as described in this chapter of the Srimad Bhagavatam.
Then the Lord married Lakṣmaṇā, the daughter of the King of Madra. Kṛṣṇa appeared alone at her svayaṁvara ceremony and took her away, just as Garuḍa once stole the demigods’ nectar.
As you said, in addition to these eight queens, Krishna also had another 16,100 wives, women who had been kidnapped by the demon Narakasura and who married Adrianna after Krishna killed Narakasura. (They were incarnations of Apsaras.). That would bring Krishna's total number of wives to 16,108.
Also, I'm a Sri Vaishnava, so I would be remiss if I didn't mention that Sri Vaishnavas believe that Krishna had one more wife, back when he was in Vrindavana and Gokulam: Nappinnai, daughter of Yashoda's brother Kumbagan, as I discuss here. Krishna married Nappinnai after subduing the seven bulls of Kumbagan, which is also said to have won his queen Satya. Nappinnai is believed to be an incarnation of Vishnu's wife Nila Devi. In any case, Napinnai may be the original basis of the story of Radha, whose name is not even mentioned in the Vishnu Purana or the Srimad Bhagavatam.
Sri Krishna every wife is very important. It is mandatory to worship Sri Krishna with his wife according to Narad puran, Narad panchantra and etc.
Goddess of fortune born as 16108 queens and Gopis of Sri Krishna.
Sri Mahalakshmi have millions forms and she incarnated as millions in Dwaparyuga to help Sri Hari and love him with different bhavas. Them being apsaras are a myth