Firstly, I am impressed with your seeking the path to Hinduism! A great adventure awaits you. You will not believe how exciting things will become. But having said that - careful....
... careful! Do not be naive.
What do I mean by that?
You are very intelligent. I can see that by your line of questioning, "how can I know which sect?" ...
That is a very insightful question! And seeing you have noted the most popular sects of the current age (there are others), it seems you are already finding your way into "the temple".
It isn't just "finding" like "luck". You are also being given knowledge, but it is given at first in small dosage.
So, keep an open mind, because there ARE sects, and when certain scriptures are presented to you as "the Bible of Hinduism", be a bit careful here.... often it is a wonderful scripture, but is in fact that of one of the sects only. It is not necessarily the way for you to decide "which sect?" ....
Honestly, in my humble opinion - there are other ways that might be more helpful. You are you. Not me. Not some member of RF. You.
So here is an experiment. Which Hindu Devatas or Devi seem to attract you, connect if you will? You may think this is childish. But I wager, you tell me the Name or Names, even if they overlap to multiple sects - yet other Hindus as myself can prubably point you to Who is calling and "which sect". In one way, no matter WHAT sect, we Hindus all respect and love each other's sects. For me that is true.
And no matter what sect is yuurs - there will be overlaps with others. And family can have a big "sway" in the matter. For example, I am Saiva but with a strong Shakta influence.
So it prubably will be. And you should go to many temples of many sects. This is common in Hinduism. It is for me, because I am what is called a Village Hindu.