Most Helpful Girl
For the piercing, I don't think it will matter much. Try to wear something with a collar that hides it. I was able to have a nose piercing when I worked at Mcd's, but that was my restaurants policy. The restaurant manager allowed it. You have to ask about the policy. I wouldn't tell them about your piercings or tatts, just inquire about it. Just maybe ask about the dress code, and piercing and tatt codes and stuff.
And I would wear a tank top under your dressier shirt, because it could help hide the tattoo. It shouldn't matter, but at the interview you want to impress the potential employer and showcase your skills. Especially you want to make them remember you, not a tattoo. Try to find a shirt that covers it, it doesn't matter that you have it, because when you work there it will be covered anyway. But just for the interview's sake, try to hide it as best you can.