How do I get my fathers house and cars changed to my name?

For the house, you need to hire a lawyer to help you through the probate process. If your father died without a will, you would require an intestate probate process in the county where your father lived/owned property. While some individuals may be able to do it themselves, I recommend you consult with a lawyer first. For the vehicle, you may be able to use an affidavit of heirship for a Motor Vehicle.