If I show up to pick my son which I have a court order to have and the mother does't turn child over to me. What should I do?

Contact the police department. They can come with you to issue the mother with the support order, and inform her by not releasing the child to you she is in contempt of a court order. Keep in mind, the police cannot force the mother to release the child, but they are there to give you documented proof that she is violating a court order. At that time you can file an order with the court, holding her in contempt.