DO NOT get into the trap of dumping dollar after dollar into upgrades for your gun.
Instead, put all that money away into a jar and use it to play every opportunity you can.
There's nothing more pathetic than a player who can't afford to pay field fees and buy paint because he spent all his "fun" money on aftermarket barrels, bolts, and bits.
Experience will make you a better player, but more importantly, it means you're actually playing paintball!
Remember, the point of all this is to get out on the field, meet people, and have fun. Not to put together some kind of showcar to impress all the teenagers on PBNation.