I would start by taking it into a shop to get the a/c system leak tested, because the compressor won't run if there is not enough refrigerant. The equipment to leak test, recover the refrigerant, and put new refrigerant in is very expensive and cannot be done at home. If you would like to save money you can ask them where they found the leak and take it home to fix it yourself, and bring it back to them to refill it with refrigerant. They probably won't like to tell you since they'll lose out on more money but it never hurts to ask. also when you go to fix the leak cap off either end of the open line and replace the dessicant container whether it be an accumulator or dryer container.
