What was the size of Sugriva's army that fought against Ravana?
What was the strength of Ravana's army?
What kind of weapons did the Vanaras use?
According to Valmiki Ramayana, the number of Vānaras in the Sugrīva army fought in the war were plenty.
In the chapter 28, one of the spies of Rāvaṇa named Shuka gives a number of Vānaras in the Sugrīva's army. That number is unbelievable in today's terms.
एषाम् कोटि सहस्राणि नव पन्च च सप्त च |
तथा शन्ख सहस्राणि तथा वृन्द शतानि च || 6-28-4
There are twenty one thousand crores, a thousand Shankus and a hundred Vrindas of these monkeys.
एते सुग्रीव सचिवाः किष्किन्धा निलयाः सदा |
हरयो देव गन्धर्वैर् उत्पन्नाः काम रूपिणः || ६-२८-५
These monkeys, the attendants of Sugrīva born of celestials and celestial musicians, are able to change their form at will and always stay in Kishkindha.
Now to know, the number corresponding to Vrinda, Shanku is explained in the later verses.
शतम् शतसहस्राणाम् कोटिमाहुर्मनीषिणः || 6-28-33
शतम् कोटिसहस्राणाम् शङ्कुरित्यभिधीयते |
Wise men call a hundred lakhs as a crore. A hundred thousand crores is reckoned as a Shanku.
A hundred thousand Shankus are said to be one Maha Shanku. A hundred thousand Maha Shankus are called one Vrindam here. A hundred thousand Vrindas are said to be one Maha vrindam. A hundred thousand Mahavrindas are called one Padmam here. A hundred thousand padmas are said to be one Mahapadmam. A hundred thousand Mahapadmas are called one Kharvam here. A hundred thousand kharvas are said to be one Mahakharvam. A hundred thousand Mahakharvas are called one Samundram. A hundred thousand Samudras are said to be one ogha here. A hundred thousand oghas are acclaimed a one Mahaugha. [6-28-34,35,36,37,38]
This Sugrīva, the king of monkeys, having great strength and valour, always surrounded by a colossal army, is approaching you to make war, accompanied by the valiant Vibhishana and the ministers, as also a hundred thousand crores of Shankas, a thousand Mahashankus, a hundred Vrindas, a thousand mahavrindas, a hundred padmas, a thousand Mahapadmas, a hundred kharves, samudras and Mahaughas of the same number, and a crore of Mahaughas whole army as such is identical of an ocean. [6-28-39,40,41,42,43]
So, the number of Vānaras in the Sugrīva were more than a crore Mahaughas. To sum up, there were a billion Vigintillion (1072).
When compared with Vānara Army, Rāvaṇa's Army is lesser strong in terms of numbers.
In the chapter 37, an incident is described where Vibhīṣaṇa sends his spies to Lanka to know about enemy's army. He speaks with Rama as follows:
My counsellors named Anala, Panasa, Sampati and Pramati went to the City of Lanka and returned here. Assuming the form of birds, all the four entered that enemy's citadel and observed the measures taken by Ravana closely. [6-37-7,8]
The elephants and chariots number some ten thousand each, the cavalry twenty thousand and there are more than a crore foot soldiers. These strong and intrepid demons endeavouring to kill someone in battle have ever been their sovereign's favourites. [6-37-16,17]
O, Rama! In these demons, a retinue of ten lacs each is near at land for each demon. [6-37-18]
O, Rama! When Ravana attacked Kubera in battle, sixty lacs of demons sallied forth with him. All of them were akin to the evil-minded Ravana in prowess, in strength, in courage and in pride. [6-37-2,22]
Weapons used by either of the sides:
Even though the soldiers in the Rāvaṇa army were less in number, they were fierce, powerful and fought with weapons like maces, spears, swords and other weapons.
Whereas Vānaras fought with their nails, teeth, huge boulders, hilltops and trees. They did not use any special weapons like maces, etc.,(For more details see this answer of mine).
Note that my answer is based off of what i read in the Mahabharata. Yudhishthira (the main character of Mahabharata) is told Ramayana recited by Markandeya (a sage) in Vana Parva. I will also only talk about the size of the Vanara army (Sugriva's).
This is from page 556:
The descendant of Raghu then caused the ramparts of Lanka to be broken down by a united attack of all those monkeys endued with the speed of the wind. Then Lakshmana, with Vibhishana and the king of the bears marching in the van, blew up the southern gate of the city that was almost impregnable. Rama then attacked Lanka with a hundred thousand crores of monkeys, all possessed of great skill in battle, and endued with reddish complexions like those of young camels. And those crores of greyish bears with long arms, and legs and huge paws, and generally supporting themselves on their broad haunches, were also urged on to support the attack.
This seems to be a huge exaggeration. One hundred THOUSAND CRORES! That means 1 lakh crore Vanaras were alive at that time. Their is not even that many people alive in India (let alone the world at this present time). So the population of Sugriva/Rama's army was huge. 1 crore equals - 10 million (10,000,000) multiply that by 1 lakh (1,00,000) and you would get this much 1,000,000,000,000 (1 trillion).
This is from page 552:
"Markandeya said, 'It was on the breast of that very hill where Rama was seated with those foremost of monkeys that great monkey chiefs at the command of Sugriva, began to flock together. The father-in-law of Vali, the illustrious Sushena, accompanied by a thousand crores of active apes, came to Rama. And those two foremost of monkeys endued with mighty energy, viz., Gaya and Gavakshya, each accompanied by a hundred crores of monkeys, showed themselves there. And, O king, Gavakshya also of terrible mien and endued with a bovine tail, showed himself there, having collected sixty thousand crores of monkeys. And the renowned Gandhamadana, dwelling on the mountains of the same name, collected a hundred thousand crores of monkeys. And the intelligent and mighty monkey known by the name of Panasa mustered together fifty-two crores of monkeys. 1 And that foremost and illustrious of monkeys named Dadhimukha of mighty energy mustered a large army of monkeys possessed of terrible prowess. And Jamvuvan showed himself there with a hundred thousand crores of black bears of terrible deeds and faces having the Tilaka mark. 2
Now the text of page 552 says "at the command of Sugriva" so of course they were all kings but Sugriva was their leader so he was like Emperor of the Vanaras. So their armies are his armies.