My sons go to SHSB and neither of them knew anyone at the school when they first started. The first day was a nightmare for me as I worried all day long but when I picked them up at the end of the day they spent the car journey home telling me about all the new friends they had made. On reflection I actually think it was an advantage not knowing anyone. Rather than staying with one or two boys they already knew it encouraged them to mix with the whole class and enabled them to choose the friends they like spending time with. Your son will soon make lots of new friends.