I haven't read much but from what I have read I have come to understand that Hinduism is not just one religion but a wholesome bunch of all kinds of beliefs. It includes faith in different Gods and the Goddess (Vaishnavs, Shaivs, Shaakts) and even the absence of faith in any God (where only karma matters). All the books are inter-related and acknowledge the role of their contemporaries. My confusion is regarding the selection of the sect by a person.
Firstly, our gotra decides our lineage which goes up to the seven (or eight) ancient sages. My first question is, are all the people from a gotra devoted to the same faith (Shaiv, Vaishnav, Shaakt)?
Secondly, if a person belongs to a particular caste, is there a text which tells them which faith they belong to? For example, Gaur Brahmans can be Shaivs as well as Vaishnavs. Because that is a broad spectrum, how to know which Shaiv or Vaishnav sect they belong to?
Thirdly, according to Jyotish, every person has an Isht Dev. Does a person's Isht Dev always coincide with their God (the faith that the family follows)?
Wikipedia says,
"A gotra must be distinguished from a kula. A kula is a set of people following similar cultural rituals, often worshiping the same divinity (the Kula-Devata, god of the clan). Kula does not relate to lineage or caste. In fact, it is possible to change one's kula, based on one's faith or Iṣṭa-devatā."
So, how would one know where they belong? I am sorry if something is not clear because I am looking for clarity. Using the above three how can we decide which sect we belong to?