Learn English – Word to call a person that works in a store

I would say that this person does not have his priorities straight, where priorities are concerns established in order of importance.

To identify, prioritize, and coordinate short-term Bacillus anthracis bioterrorism research for public health response, the Centers for Disease Control and Prevention (CDC) convened a meeting in Atlanta on December 10-11, 2001, to obtain input on research priorities and improve coordination with federal partners and other stakeholders.

A general term is hospitality worker. This broadly refers to someone who works in the hospitality industry, which also include, for instance, restaurants.