Do we have to be with a parent if we’re under 18 ? Even though they gave us permission to get it

Yes, if you are talking about a piercing. You can't get a tattoo period until you are 18 years of age even with parents consent. It is against the law.

Yes the parent has to be there with some kind of id for you, like birth certificate or school id and there id.

Yes but not for tattoo you have to be 18 or older to even get a tattoo