How and where can i get a horseback riding sponsor?

I am an excellent rider, have jumped four foot three but can jump much higher if asked, and can deal with and train unruly horses and ponies. Do you know if there is someone looking for a rider to fix or ride their horses or where I could look to figure this out? I am pretty young but can do anything asked. I would be happy to show off horses to get them sold or to just raise interest in them.

Unless you ride at a large barn with lots of people who know your ability, or you know people in the right places, the sad fact is that nobody is going to be interested in hiring a child to do things like that. Maybe ponies or people trying to sell their horses as beginner safe, but i would say just hang in there and keep riding until you're older. Also, try to network in with people.. Ask people if they've got horses to exercise etc.