Go to a rental field and just play with walk ons. Bring a buddy with you.
Only thing you MIGHT want to do before you go rent, is buy your own mask. Find a local store and try on everything they have, shaking your head a lot, breathing heavily, jumping around.
Once you try on everything and realize the JT spectra or JT Flex/Proflex is the most comfortable, buy one, and then go to a rental field and have some fun.
Don't get caught up in dominating firepower right now. Paintball guns that look like real guns are usually really cumbersome for paintball, pointless aesthetic accessories that get in the way. With a paintball mask it is tough to actually bring a buttstock up to your cheek.
Best choice is just to get some buds and go to a rental field with or without your own mask.
Really, don't overthink this. Don't buy anything (except MAYBE a mask) and just go play rental paintball and have a good time. Avoid fields with a lot of guys wearing flashy clothes like out dated motocross riders. Find a field with a bunch of people (fathers and sons) and guns that look like http://i827.photobucket.com/albums/z...tippmann98.jpg
this or this http://i108.photobucket.com/albums/n...ps30d6e42e.jpg
The people should be wearing sweatshirts or camos or a mix.
That is where you want to play.