Hi,
Since your son was able to change your account admin account to standard, he must be having admin rights. You can ask him to log in back and change back your account to admin one. Only an admin can change account type.
If both of you don't have admin rights by chance, you may try System Restore from Windows RE.
https://support.microsoft.com/en-us/windows/experience/backup-recovery/windows-recovery-environment
If issue still persists, you can refer Fix 2 here:
https://www.kapilarya.com/solved-lost-administrator-rights-in-windows-11
Let us know if this helps!
Note: Included link(s) in this reply refers to a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.