You do need to have a job in order to be able to rent anything. And not just any job. In San Diego, for example, it would be tough (maybe impossible) to find a rental apartment, even a studio, if your income is less than 30k/year. That’s $15/hour full-time. So, jobs at Wal-Marts and Burger Kings are insufficient. SoCal is expensive.
If you’re upside down on your mortgage and you lose your job, becoming homeless is a real risk.
There could be some government programs aimed to prevent that, I don’t know the details.