Can't access App Store on Newly Updated 2015 MacBook Pro

Hello,

I had been having some issues updating my MacBook pro for a while and finally manually updated it about a week ago via the app store to Big Sur. Since updating I haven't been able to log in to the App Store at all, and it won't accept my current email and password at all. I even changed the password to see if that would work and it keeps telling me my account is locked. It had initially been auto-filling the email info with the email I used to use when I was a kid and first got my iTunes account that I haven't used in years, and after trying with that a few times it also didn't accept it or any of the security question answers associated with it.

Does anyone know how to circumvent this issue? It's been telling me to contact iTunes support, but provides no method or button to do so.