The best wazy to get anything peirced is to go to a shop that does tattoos/peircings or solely peircings. It's also much better if they use a needle, cleaner and less likely to get infected. The machines are harder to clean and a lot of the people that use them don't know how to clean them out properly.
Always go somewhere that uses needles, even if it doesn't get infected, the likelyhood of complications is a lot less. TBH, you're a lot better off going to a shop than the mall for that sort of stuff. If you're worried, you can call up the shop and ask them how they clean out the machine, and aftercare and stuff. Also, internet reviews are really helpful.
I don't think you have anything to worry about, but if it's something that is bothering you, you can always get your blood drawn to find out if you contracted anything.
Remember though: Peircing guns BAD news! Needles SAFE! They throw them away after every use.