I didn't add my bank account details during registration where I can receive payment. If my book sells, how do I get my cash especially if I didn't also add T.I.N.?
If I were to update the former information, how do I do that? And how do I tell the difference between received and pending payment?
If you are not in North America or western Europe, you either have to wait until your accumulated royalties have accumulated above $100, which is a long time for most authors, and get a cheque mailed to you, or else sign up for Payoneer.
I've never used Payoneer and have no personal knowledge of how good it is, but I do know some people seem to find it useful. There are a lot of threads about it in the Payments forum.
To get to your account, click Bookshelf at the top of this page, then you will see a link to your account at upper right. You won't get paid without a TIN or other number. Try your tax number from your home country.