I was homschooled and back in the 90s I played little league sponsored by the city, so anyone could join. This was in Oklahoma and back then I heard that I could join public school activities because we pay for it with our taxes, but we never did.

Side note, Oklahoma has homeschool rights in its state constitution from inception. When I finished homeschool, I went to a state college, no diploma or GED required, and when I got an associate degree, I applied for and received an honorary high school diploma from the state. I wish more states were like this. They didn't let my situation get in the way of my progress.