I just recently got hired for a job, somehow this employer got into my private medical information and now won't hire me. Is this legal? NEVER SIGNED

Employment in California is at will.  You can be fired with or without cause except for discrimination.

In terms of what you are talking about, if you were hired, they won't continue with it because they have private medical information? How did they get the private medical information? Did you sign releases? Does your job require manual labor wherein you are handling heavy or dangerous equipment?
You are not telling the full story.  Try www.attorneypages.com and also the California Dept of Industrial Relations.