What do I do if I have no auto insurance and someone hit my car?

If the person who hit your car is the cause of the accident, then it doesn't matter if you have insurance, since the other driver's insurance company is obligated to pay for the damage (assuming that you can prove your case).

If the case the way around then the case might be a big problem. Never hesitate to get insured. It is in the mind of people saying they're costly. Think of it hitting others car.