The forum works on Trust Levels, so the more you interact with it the more it assumes you know what you’re doing. 
There are a few abilities that are limited at lower levels (the main one being uploading pictures), but getting to Level 2 is easy. You just need to log in for 15 days (not even in a row), read some topics, and throw a few likes about. 
There’s more detail on each of the levels (and how to get there) in Trust Levels.
I’ll chuck a link in to the Welcome Topic too, as that’s the main info hub. There’s loads of stuff in there, but you don’t have to read it all in one go. Dip in and out as and when you need it.