It goes toward just living. If you have a job (gas), you have to eat (food), you need clothes to wear to work not only clothes you need shoes, underwear. You need somewhere to lay your head (house or just rent) not to mention (heat, water, etc.) I can go on and on.... so just living.
All of these things could easily be supplied by a part-time minimum wage job if:
You buy all your clothes from thrift stores. There's nothing wrong with buying used clothes as long as you wash them. A lot of the time when you buy clothes from store they can be returned which means they where already worn once. Also use thrift stores to buy anything you may need or enjoy using (like books).
You ride a bike to work (it helps if you live close)
You eat frugally (Beans, rice, and pasta go a long way and are cheap). Eat vegetables that are abundant and in season. Eat only small amounts of meat. Eat left overs and don't waste any food. Always buy on sale and use coupons only on things you are going to buy anyway. Do not eat out. If you don't want a lot of dishes, don't eat messy foods. If you have the space and a few tools, try starting a small garden.
Try these tips:
For shelter try sharing rent with others. Get a room mate. Not owning a house eliminates a ton of expenses (taxes, repairs and other maintenance like lawn care, and insurance).
Bills can be small if you're careful. Sharing rent can also mean sharing heat. Minimize the time you spend in the shower. Hang clothes when you can instead of using the dryer (which saves a lot of electricity). Sharing the internet with roommates can also mean splitting the internet bill. Use a prepaid phone and use minutes for stuff that's important (or get a headset and try skype, for a few bucks a month you can call anywhere in the US through your internet.)
Be careful with toiletries. Don't buy a lot of cleaning products you never use. For toilets and sinks, bleach and water in a spray bottle usually can do the trick. For tubs, take some used towels and lay them down in a water and bleach mixture you made in your tub. Be sure once you mix the allow it to air out before re-entering to avoid fumes. Use paper towels for wiping your mouth and use regular used dishtowels to wipe off messes.