I was hit in the rear end of my car over a month ago and I am having a hard time trying to get the person whose car it is to pay me how do I start a small claims against the person

Are you in the U.S. Which state? Contact the nearest clerk of (state, not Federal) court, or look up the clerk of court online.

Usually your car insurance company handles it for you.

Usually your car insurance company handles it for you.

Assuming you have collision coverage.

Why haven't you filed a claim against their insurer?