You're son actually reminds me when I first started cubing
When I was like 9/10, I would cube and average sub-40 in 3x3 and same for 2x2 which I averaged like sub-15. Also sub-20 for Pyraminx as well.
However, I think that I and a little bit old (I'm almost 13) and I average way faster than this.
You should definitely ask him if he knows anyone in their school that cubes if he's not homeschooled
I know that I used to hang out with one of my cuber friends in school who averages sub-20 (he doesn't cube anymore

)