I noticed the hierarchy in the Forum, so I mean to ask, are there some sections I need to avoid since am just a newbie? Can I contribute to any thread despite the OP's rank?
Yes, avoid posting in the mega threads where there is no discussion is happening all you can witness is full of spam created to meet the quota requirements or as troll, etc.
Post in any section where you feel comfortable but as a newbie you can explore everywhere and find which suits you better for the knowledge you have because in bitcointalk you're a newbie doesn't mean you are lacking knowledge. There are many exceptional low rank members are giving detailed explanation about technical related things which I really don't have any idea.