Admin

Hello, LTweetstar.

Sorry that you're having this problem with your Mac user account.

There are no "administrator details" to reset in macOS.

The best you might do is create a new user with admin privileges and use that whenever you wish to update and change certain settings on the Mac. In fact, best practices suggest that you do not normally login to an admin account for everyday use. This is especially true with PCs, but can be advantageous on any shared Mac as well. It's usually a good idea to have a second admin user account on the Mac for troubleshooting purposes anyway.

To create a new admin user, go to System Preferences > Users & Groups. Unlock the panel, click the plus ( + ) button and fill in the blanks. Make sure you make the new account an administrator.

What changes are you currently unable to make with your present admin account?

If the Mac is giving you grief, and if rebooting your Mac doesn’t fix things, see if the problem still happens in Safe mode (hold the shift key down at startup). It can take much longer to safe boot (10 min) so be patient.

How to use safe mode on your Mac - Apple Support 

Safe mode disables loading third-party drivers, forces the OS to clear certain caches and logs and does other miscellaneous housekeeping. It's non-destructive to user data so is safe to do. Very often certain weird software behavior is corrected by simply logging in this way as a troubleshooting method. When you're in safe boot, the machine will not be at its best performance, especially with graphics, but that's expected.

Does the problem persist while in Safe mode?

Exit safe mode by restarting your Mac normally and re-evaluate the issue again.

Please do not duplicate post, as this clogs up the forum. Please be patient and someone will be along to answer your question in due course.