I have a person that is sting with me that has no lease agreement and has never paid rent in California. She has moved her 20 yea old daughter
In and her 2 year old son.

How long have they been there? Is this a private residence or an apartment?

Basically you give them a vacate notice and if they leave you go to court for an eviction order. We need more details to be specific.

Yes in general with the information given, you will give them notice and then evict them.