If your goal is to start a new team, your best bet is to visit fields in your area. You're fortunate that you have at least two fields near the Des Moines area (Archery and ICU. Maybe 1-2 others???). That will keep your travel time short, since you'll be dependent upon a ride to & from the field.
Get to know people at the fields, and give people some time to get to know you and how you play. That is by far the best way to get to know other paintballers and form a team. BUT, you do not need a "team" to enjoy the game. You just need as much field time as your free time and spending money will allow.
Being on a team and attending events is a huge commitment in time, money and travel. Not saying it's impossible for younger players, just incredibly difficult.
Before you enter in a tournament you will need to have saved enough money for entry, paint and travel. You'll need someone willing to drive 2+ hours both ways and willing to spend all day at the field (a hard thing to ask from a non-paintball-addict).
KW in Waterloo holds a few beginner (D4/D5) events each year. Go in expecting to play hard & learn a lot, rather than expecting to win a lot of games or prizes.
Or try to join an existing team through team tryouts. They are usually held in the early spring each year.
In the meantime, play as much as you can, and try to play against players that are better than you.