1 - You need to check with the city to see what kind of permit, if any, they require for camping on your land. My guess is that during Bike Week in Sturgis, they are fairly lenient with this.
2 - You need a license to allow you to sell beer. This will probably be hard to get as you are not an establishment. The way I have gotten around this in the past at motorcycle events is this: Find a local nonprofit that you like and can work with. Offer them the opportunity to sell the beer, and agree to allow them to do so in exchange for splitting the profits with them. They can get a special, one time use permit for a nonprofit that will allow the beer to be sold. They do all the work, they split the money with you, you make a profit and help out a local charity at the same time. It's also great advertising
and p.r. A win-win!
3 - For the entertainment, you may need a local noise permit. They are very easy to get from town hall.
4 - Check the local regs to see how much security you need to hire (some places require hiring X number of guards for every X number of people, some don't have this requirement).
5 - The dirt race track should not require any permits as long as you are not charging anything for the racing, but you might check just to make sure.
All of these requirements that you need can easily be obtained through the city or county permitting department. You just need to spend a little time down there, get to know them, and they will usually be quite helpful. I go to Sturgis every year, so if you get is up and running be sure to let me know! Good luck!