You have committed a summary offense is this is your first retail theft and the amount was under $150. Your punishment if you plead guilty or are found guilty will probably be a fine and perhaps attend some type of retail theft school. However, there may be a diversion program available that will allow you to earn a dismissal of the charge. You should speak to a criminal defense lawyer to see if you have any defense or if there is a diversion program. Although a fine doesn't seem like much the ramifications of a criminal record tor a theft offense can be devastating. Good luck.
You and your family should contact a defense attorney immediately. Often these matters can be resolved through a diversion program not involving the juvenile court.