Administrator
How do I find my administrators name and password
iMac 21.5″, macOS 11.6
Question marked as
If the Mac is not your own, and belongs to a school, or employer who remotely manage it, then you were never intended to have administrator privileges or know the password.
If you own the Mac, without remote administration, then the administrator name would be your own shortname and the same password you use to log into the Mac. This can be set in System Preferences > Users & Groups.
Otherwise, if there is an issue with paragraph 2, then take your Mac and proof of purchase to an Apple Retail store, or Apple Authorized Service Center and get resolution.