I was in a car accident and I'm not sure if it was my fault or not. How do I proceed?

Do you have insurance? If you do, immediately call and have the insurance company assign you a lawyer to rep you (usually they have that in your policy).  If not, was there a police report? What did it say? Start keeping tabs of your expenses and bills and keep a journal of any pain and suffering, take pics of you if any bruising/bleeding and of the car.

If you are concerned about the efficacy of your policy, call a personal injury atty for a consultation and possible representation.  Try attorneypages.com.