Canter sets, trot sets, grid work
Lots of circles and figure of eights is good for flatwork. For jumping makin sure the horse is using its brain,grids!! firstly set up a bounce then set up a jump that is one stride out then set up a bounce. Make sure the jumps are low so the horse doesn’t rush towards them and hit them :)
Some leg yield, shoulder in, circles, transitions, serpentine, figure of eight (this is all to make your young horse develop, make it think forward, listen to different aids and these make horses supple) and once you manage to get it all perfect on a flat you can add pole work, cavaletti, grid work with small jumps (these are good for balance, muscle development (top line) and encourages hind quarters even more.
Then as you progress into grid work you will see whether your young have a thing for jumping. Is it positive about approaching the jumps? Is it progressing and willing to jump higher and higher? If so you can start some jumping exercises