When my horse was a yearling, I did a lot of ground work teaching him to respect my space, like using a whip or your hand to *gently* tap his hind end to step away while his front end stays still -- that kind of thing.
I also played around with him to the point that he accepted me crawling under him (although I really don't recommend doing this ... I was a pretty good horse person at this time and my horse was pretty much dead quiet), hugging him, even leaning on and climbing on him a little. It's a good time to practice getting your horse to stand patiently at a mounting block too, even though of course you won't get on his back yet.
You can also encourage him to follow you over tarps you've spread on the ground, over small obstacles (that you step over), into water, all that good stuff that horses are afraid of. I even draped tarps over my horse ... and if it's any measure, he's eight now and will stand for hours in crossties, pick his feet up on verbal command, follow me with the lead slung over his neck, let me wave a flag while seated on his back, and wait like a champ at the mounting block. The only thing we didn't do was trailer load regularly, and I regret it ... he really doesn't like to load unless he's seen another horse walk into the big dark scary box first. ; )
Seriously too ... Please. Get a trainer. You're really brave for wanting to do this, but it would be terrible for your learning experience to land your horse with permanent training issues and/or you with a serious injury. Even really experienced riders can get really hurt working with young horses, and even really nice horses can hurt riders. For example, my super-sweet, super-docile horse accidentally threw a professional rider once when he was a three-year-old, and broke half of the guy's ribs ... and working with older horses who have training issues is a whole lot worse, because bad habits cement with each time they go uncorrected.
Also, try moving your horse to another property with other horses ... it will keep him from getting bored, and the other horse people will keep you company too : )