This isn't a personal attack here, just making a statement based on experience. (Just FYI, I don't want anyone to think I'm attacking)
You can actually have a debit card that isn't cosigned when you're under 18. I had a debit card at 16 with no one's name on it except my own, and no one cosigned for it. My mother was indeed on my bank account as a partner, but there was nothing on my debit card, and I had bought things online at 16 (IE, one of my first vibrators) and was not given any check into about my age. So you don't have to have an adult on the card nor does it have to say anything about you being underage, because mine didn't. I did, when I turned 18, go close my bank account and open a new one without my mothers name, and they gave me a new debit card, that looked exactly the same. I also don't believe that you can verify through a debit card, and if you can, it's expensive and very tedious to do. But yeh, cards don't have to have anything like that on it
OH AND. On topic:
Lots of lubricant, lots of foreplay, and you may want to work your way up. There are vaginal dilator kits available on EF also, that will help you work up to that.