Penalty for stealing from a Walmart in AZ?

That would depend on how much you stole and why and how you stole it. For petty theft, the definition of which depends on the state, but which commonly means less that $400 stolen , the maximum penalty is usually a year in jail , if you pay back the money, and have no prior criminal record. Plea bargains as common , especially if you turn yourself in.

If you are asking this question because you are planning to rob Walmart , don't do it. You are more likely to be caught than you might think -- they have security systems in place-- and even a short jail term will damage your reputation and employment opportunities forever.