How can these 2 have rights as tenants when they are not paying any money. Could I just go to my neighbors house and say I am not leaving and just live there?
Under CA law, that makes it a landlord/tenant relationship until proven otherwise in court.
In CA, and other places, you can sign a lease, move in, not pay one cent of what you have agreed to pay, and it will take several months to force you out.
It is meant as "protection" for poor people who may lose their jobs.