Kids pick up on this stuff like ducks to water. My son was racing RC trucks at 6 and winning in the novice class but that's what I was into at the time.
I'm not into electrics either but Pro Boat has sold a lot of those. Go with hobby quality as department store boats are junk.
I'd rule out racing for now as I don't know if there is a class for them. Racing also involves joining a sanctioning body which isn't cheap and also a lot of driving to races. Some do have Novice classes.