Qualifications
Other than your funny, charming, and people-pleasing heart of gold? You'll have to be at least eighteen years old. Sorry youngins.
A certification from either the Pharmacy Technician Certification Board or the National Healthcareer Association will also definitely come in handy.
An advanced degree is not necessary. Most of the little training you'll need to do this job ("This is where we stock the medications. Match the medication on the slip of paper the customer gives you to the one on the shelf.") happens on the job.