re: New Job Changed Schedule on First Day...Any Recourse?

I'd go to the hiring manager and inquire. It could be an honest mistake.

It's also entirely possible that after you were hired they identified another candidate they wanted more than you and switched your schedule hoping that you would quit or moved your schedule to accomodate the other employee. I've worked for such a company before.

I believe LA is a right to work State and under the employment at will statutes I think the employer reserves the right to change schedules that is unless you are a unionized worker at which point things get very messy.