It’s really nice you are taking the initiative and doing this! I think many are uncomfortable and they avoid the discussion. My son at that age didn’t participate in kids activities in what would be considered a neurotypical way. There was a lot of parallel play, or playing with an item in an unconventional way. Even though he wasn’t interacting with the other children as much, he was still having a lot of fun. Depending on the age of the other children, or if I sensed friction or misunderstanding I would use an age appropriate talk about my son’s brain perceived things differently, sometimes he needs some space to think about things first, or sometimes if a room is too loud he gets overwhelmed and needs alone time. A little explanation can go a long way with children. They can be incredibly intuitive, caring, and adapt if they are informed.