Can we bring our own guns and mask ... if so what would it cost for air and paintballs

You can get boxes of the paint at Time2paintball, in Cerritos, that come with half off entry. It will save you some money.

$37 for entrance and it depends on how many balls you want to have 500 1600 and 2000 the 1600 is $55

Yes you can but it's restricted to how powerful and how. Many bbs it can shoot in full auto. Must be checked out and approved before hand