Team Qualifications
Good news. There's no such thing as NCAA teams for triathlon. So you don't have anything to worry about. Isn't that great?
What you're looking to join are clubs that might one day become varsity teams, if everyone does really well and claps when Tinker Bell dies. We're not sure about the exact logistics of the vote, but we're almost certain it has something to do with fairy death.
If you're on one of the very few varsity teams (again, these only exist for women), you will be held to the same standards of any other NCAA athlete, except without all the benefits of being an NCAA athlete. That means keeping the grades up, working hard, and steadily improving. For men, it means going to your club, competing well, and being a good example off the track. No one wants to sponsor a sport that produces a bunch of jerks, so you're going to have to be on your best behavior at all times.
You might also be on the hook for your own equipment. Unless your school's club has a bunch of bikes and wetsuits lying around (and who wants to wear someone else's wetsuit, right?), you will be providing your own.
Additionally, you need what any triathlete needs: endurance, and when that fails, pure willpower to keep going. This is a sport where the person who doesn't give up is the one who wins, and that had better be you.