No matter what you do, you have to repair everything now by spending your own money. You can sue the tenant later to recover the extra cost not covered by security deposit, but you can sue him/her anytime in the next year. Your first priority now is to repair the damages, and keep all the receipt.
1. Garbage disposal: https://www.youtube.com/watch?v=4Mooxhkx_Cc
2. everything else in the house, doesn't cost much to repair
3. Lawn: Sept is the best time of the year to reseed. http://www.wikihow.com/Overseed Do it now.
After you fixed all these, found new tenant and have time again, sue him. Doesn't matter if his aunt is a lawyer, you have the law on your side.