With the Race Tracks of the Game Corner, How do I actually use it? I do not understand how it works at all.

Click the racetrack on games corner and you can either click ADD POKEMON at the top of the page to add your pokemon to the races and wait till another player races it or if you have a pokemon the same as one that's already up you can click RACE POKEMON at the side of the pokemon you want to race (same pokemon - for example if the pokemon is cursed you have to have the same cursed one to race), plus if the pokemon is a high level you must have the trainer level to actually take them.

I just added a Pokemon, That's shiny, Up at the Racetracks, My Trainer Level is over 800, and as is my Trade Cap, and it won't let me actually do it still, and it won't let me race the shiny I want to race

Lugia2000 you must have misunderstood. Adding a Pokemon to the racetracks is just like creating a bet on the 50/50 game. When you add a Pokemon to the racetracks you must wait for another user to race it. When you want to race your Pokemon (a shiny one in this case), just look for another shiny Pokemon and click Race Pokemon

I tried to race a shiny beforehand and it was a Level 27 and I was using a Lv.Five Hundred Thirtysomething that I was using, and I think it's just the Level caps thing :l

It is. If the level of either Pokemon exceeds either side's trade cap, you can't do it. Like Robath mentioned, it's like creating a 50/50 trade. You can't create one if a Poke on either side exceeds either side's trade cap. IF your trade cap is 700, and the other person's is 500, then you can't offer a Pokemon above level 500 and they can't offer one above level 700. And the Pokes have to be exactly the same (level, moves, stats, owner, etc don't count), like you can't race a ShinyVileplume with a ShinyClaydol. You have to race a ShinyVileplume with a ShinyVileplume. Non-colored Pokemon are different. You could race a normal Houndour with a normal Cyndaquil.