Qualifications
There are virtually no qualifications needed for this gig. You need to be able to walk, talk, and breathe.
In theory, if you work at a bar code enabled station, you really don't even know how to "make change" (not a euphemism for going to the bathroom). The computer does everything for you. As long as you can find the bar code and slide a couple pounds of whatever across vinyl, you're pretty much qualified.