Things to ask a piercer before you get your belly button pierced?

im calling this place where i think i want to get my belly button pierced at. im in high school so im for sure gonna ask if i need parental permission. what are some other things to ask? if theyre sterile with the needles? how long after before i can go swimming? thats all i can think of right now. what are some other things to ask and how should i ask them? thank you tonns!(: