In my area (SLC Utah) schools started Spring Practice at the beginning of April. I can guarantee that no matter where you live schools have some form of football practice going on 🙂
If he wants to get involved have him go talk to the coaches. He'll make a better impression if he does it himself (instead of Mommy or Daddy going with him)
Make sure you set the expectation that football is a TEAM sport. Not everybody gets to play, but everybody helps the team get better.