My roommate has specific boundaries that I don't understand.
That's not good. Why wouldn't you understand his boundaries?
They are confusing to me.
If you don't know what your roommate wants, you should ask them about it. It's okay to be confused.
I'm not too good with that kind of stuff or talking about it, guess I'll just smoke weed instead.
If you just smoke weed, it won't help you understand what someone wants or needs. You need to have a conversation with your roommate and asks questions when you don't understand so that you will understand his boundaries.