Monterey installation freezes, probably due to disabled Secure Boot, can't modify it, though

https://support.apple.com/en-us/HT202860

should help you establish an administrator password for your Mac. Once you have that, then the administrator to manage secure boot will help.

Note if you tied your Mac to an Apple ID, that account may be registered as the administrator. AppleID is the same ID you use to open iCloud, and Apple Support Communities.

The other thing to keep in mind before you upgrade, you must backup your data. While this is a moot point since you erased your drive, it should help others who run into the same issue. There is really no reason to erase your drive before upgrading, unless you are sure you don't have sufficient space to install, and you want a quick way to have a clean slate. When you do this, make sure your backup is cloned in two different places before you erase.