Apple Card family sharing

Does anybody know how to figure out what family you used to be a member of? I am going through a bit of a conundrum called identity, theft, and figured out from Goldman that there was an Apple Card opened, but I never knew anything about it because I was a co-owner. I can’t get any information about the account or anything because I don’t have any information on what the card number was what the account number was who is it? You know anything so if anybody knows how to see what family you used to be a part of or any type of clue on how to handle this because it’s not on my credit report so figure out I’d ask the Apple community to help a fellow Apple community member.