Don't take it seriously, chat to other players as much aspossible, and don't worry about charging in like a mad fluff and getting shot quick.

Honesty and safety are key too.

And from a former paintball, now airsoft convert, I can safely say once you go 'soft, you never go back.
What site are you playing at, out of interest?

Oh, and because new equipment is expensive, rent or borrow first - DON'T BUY. Purchasing equipment is for later, when you know for certain it is for you.

Jeans and a t-shirt are usually fine, unless you have some camo already sitting around. Hi-cap Magazines are usually a must unless you're in a dedicated mid or low cap group. Above all is honesty; you may get a way with not calling your hits a few times, but people will notice and then you will get a bad rep. and/or an entire magazine at close range. Mostly though just have fun and remember its a game.

i have not really done it ...but just try not to get hit

A light tactical vest, a gun(normally for zombie games, you will have a pistol or smg with 1 or 2 mags but depends on zombie game type), a lot of mags if they are Mid-Cap (a few if they are Hi-Cap) if allowed, goggles or face mask.

Take it slow especially around corners, make shots count (3 to chest, 2 to head if head shots are allowed), keep your eyes open, and aim down the sights for all shots(no hip-fires).

FYI, BB's can hurt more then paintball depending on the weight of the BB. 0.12g =weak 0.25+ painful especial 0.40's,0.43's,0.45's,and 8mm BB's.