Welcome to bitcointalk! I’m sure your brother would have told you some things about the forum. Don’t forget to read the forum rules and the sticky threads on this board. I made a list of a forum related threads that will help you understand the forum.

Unofficial list of (official) Bitcointalk.org rules, guidelines, FAQ

Merit & new rank requirements

[Guide] searching effectively

Apart from reading the forum rules and merit system. You should also explore the forum and read topics that strike your interest. The forum had over a decade of topics and resources on crypto discussions, a simple search would give you answers to questions you may have.