My dads girlfriend had an argument with my dad and she told him to leave. I have no idea what to do. She hates me.

How old are you? Do you live with your dad? Does the house belong to the girlfriend, or is she renting and the one on the lease?
If you are a minor then this is between your dad and the girlfriend. It isn't up to you to know what to do. What does HE say about it? Do you have a mother you can stay with, or other relative, while he sorts out a place to live?