My landlord house has been sold I don't know how long I have before the new owners give me a writ of possession

The new owners have to honor the terms of your written lease. If you don't have a written lease then you are a month-to-month tenant and they must give you 15-60 days notice to move out. The actual amount of time they have to give you depends on your state's law. If you haven't moved out within that time then they have to file a lawsuit for eviction.