If you decide you'd like to open your own piercing parlor someday, start educating yourself by contacting the Association of Professional Piercers or a similar organization. They can guide you to the proper classes, courses, and readings you should perform before you open your shop.
If you're the piercee in a piercing parlor, you have certain rights. Among these is the right to be attended to by a competent, professional and sober piercer who is experienced, and who uses sterile needles, gloves, and other equipment, so that your health is protected.