How do I delete a very old fake account, I’m worried I’ll loose my real account

So when I was back in school I made a fake Facebook profile, me and my friends would use it to do a loyalty check on our partners we was like 15 at the time, I logged into my main account on my new phone and found it logged in, I wanted to deleted it but it seems to just show my actual profile picture and now scared to delete it incase I delete my actual account and it holds soo many real memories when it asks for password to confirm, I’m scared to press continue as I don’t want to loose my main account but I’m ovy grown up enough not to need the fake one