Contact British Cycling. 0161 274 2000 They do a lot for kids through their GoRide programme. My son is busy for every Sunday of March doing track cycling at Herne Hill Velodrome with GoRide. Best of all it is free and track bikes supplied free as well!
The GoRide events take place country wide, so your area should be covered. I remember them doing a MTB skills course for your lad's age during the holidays last year at Leith Hill , the lucky kids! My boy was just too young ( 9) so could not go 🙁
Like I said, they do events across the country. If you don't get any joy then email me and I will find out through my son's cycling club if they have some leads for you ( Sutton Cycling Club- very one the ball youth cc).
Hanno