U had a hit n run n u were in juvenile court and the majistrate said u could face up to 250 in fines and 90 days in ydc so u took a pretrial u dont care about the money what should u do to avoid ydc?

I would recommend a good lawyer, first of all. By the way you stated this question, I assume that you admit that you are guilty of the charges, so plead guilty and see what your council can do in the way of a plea bargain. Also, if the person you hit sues, try to settle without going to court.
Hope that helps.