Start witg flatwork some poles and some hacks with small osbtacles. Also gates to open or between trees. He'll tell ypu with time what he enjoys to do. I had big pedigree dressagers became jumpers and big pedigree jumpers became dressagers. Not because you have a quarter horse means western or a thoroughbred racing.
I agree with what Juanmi said. Try him out with jumping, dressage, basic flatwork, to see how he goes best. You can probably train him to do whatever discipline you ride, but it is always good to do what he can do best.
I hope this answered your question!
It is hard to tell when i haven't see the horse moving. Horses are good jumpers and have good movements by nature. I recommend you to start with building a nice flatwork base. Then try him jumping. If both of you feel confortable jumping, you can start training show jumping. If not, you can train for dressage. If you do well at both, you can do eventing.
Hope your question was answered.