The number one priority at any piercing parlor should be cleanliness and concern for your health. If the one you're considering is not sparkling clean and well-lit, bypass it for another that is. It's pointless to endanger your health just for a body decoration.
Any reputable piercing parlor -- from an earring kiosk to a full-service business -- will be willing to follow the local health rules, which can vary greatly according to jurisdiction. You should look for the relevant permits, which should be displayed openly, and be sure they're current.
Be prepared to present a valid form of identification when you go to a piercing parlor for a body piercing. There may be age limitations in your local area for anything other than basic earring piercing, and if you look younger than you are, the parlor may (and should) ask for ID.
