Be sure you pick one that your friends (or kids friends) are part of. Otherwise, its unlikely the ball will ever get passed to you.
Unless you (your kid) is a superstar. (In which case, you’d probably already know of the leauges)
One son played after the “leauges” left with his classmates, so that was ok. The other son tried to join, and had a rotten time, for the reason noted above.