Just let it be a horse for a while, when people do begin riding it, take it for gallops through fields and forests, wherever possible thats not in a circle round and round track because it will make it so much easier for them when they begin on the track because the surface is more level and they will want to run if they enjoy it and you can notice that out on the trails because the differences in the sceneary make it more interesting for the horse.
A lot of groundwork on the leadline, lungeline, and longline will make the horse much easier to control while getting ready for the race before the jockey mounts up.
In all honesty, I think racing horses at such a young age is a mistake, I used to help care for a tb that was one of my mom's friends, and she was always getting injured on the track, from one day's lameness to the next month's injured fetlock. It just all seemed to connect to that her bones hadn't had time to mature. I think it would be best if you started out a year later then most tb's, if that is possible for you. I know some people cannot do that because of training troubles and not being able to find a trainer to work with a horse that isn't going to race at a really early age, but it will be so much better and healthier for the horse. Think of it this way, would you want 2 years of fame an then a horse that's lame for the rest of his life? or a year of fame and a whole life ahead of him.