Any suggestions on what to do on Facebook, I'm new?

[Ascendancy]

First of all, fill in your complete profile. Then you can upload your photos and create various albums that you can share with your friends. Write on your friends' walls and you'll get notes on your wall too. Comment on your friends' photos.
Besides, as you already know, you can take various quizzes and publish them to your wall or add to your profile/info also.(Take this one : What does your birthday month reveal about you? It's really fantastic!)
Apart from this, for fun, you can play games like Vampire Wars or you can even send gifts to your friends by collecting points.

Actually, there's nothing much to tell about Facebook. Just keep browsing for stuff and you'll automatically know what you wanna do and what you don't.