Zeb a great starter IMO is a Spyder. They are very simple and easy to upgrade your self by modifying them and buying extras as you get into it. and very low priced.
As for tips. Man its really an experience thing. RUN fast shoot a LOT, but more than enough paint. You can really pin people down. OH and TALK a LOT with your team. It is uauslly the team that works the best together and communicates that wins. Also depends on the game, speed ball or more of a wildernes thing, attack and defend, each require different apporaches.
Dont get shot in the junk. Or the fingers those are the worst. LOL