For starters, welcome to the sport brother! You're going to love it!
Now for details about a team.
Well first off, it depends upon what kind of team you are talking about. A speedball team, woodsball team, or both?
It also depends upon what league you choose to play in.
Most tournament leagues around use the APPA, a ranking system for players. Anyone can make an APPA account by going to
www.paintball-players.org. You will be given a sort of id number when you register an account on there, don't forget your username, password, or id number for the account, because for tourneys if someone needs to add you to a roster, they need to have your full id number.
Requirements for a team- Again, it varies from team to team, league to league. Some teams who play in tournaments just play for fun, and may only practice once in a while; other teams may be very hardcore competitive, and practice every week. Expect to spend $200+ a month on practice costs, tournament costs, and also food and gas mileage easily (and if out of town, hotel costs). Transportation for practice/tourneys, free time on weekends, especially Sundays, and some sort of income are necessary for tournament paintball. It is much easier to join an established team than start one, believe me, I've been there, done that. You need to be dedicated to your team. The more you show up to practice, the more likely you will be put in to play a tournament; it's not like little league where every player is required to get some play time. In terms of your skills, practice, practice, practice. Lots of helpful tips on PbNation, and Youtube on improving your skills. I hope I was of some help to you, wish you the best of luck if you decide to get into the tournament side of paintball!