Travel Trailer Porches Is It Illegal To Have A Travel Trailer Parked Outside And Have Occupants In It?

Is it illegal to have a travel trailer parked outside and have occupants in it? - travel trailer porches

I live in California and have friends to stay out of my house in a small trailer. Is it forbidden to live there? In total there are seven of them, and have no place in my house for them. I wonder if I should get some kind of permission, or how it works. I do not know how long she will be there.