forgot admin name and password for my mac pro air

DO NOT change the name of any User, especially not the admin user. One little mistake and you will be locked out of your Mac.

Instead of changing the name of a user, create a new userid that is more to your liking, give it Admin privileges, at least temporarily, Use it to copy one over the files of the Username you with to abandon. Then if it is to be a regular User, turn off its Admin privileges.

After a few weeks with no problems, then you can freely delete the old ID.

You would have to go to system preferences, then users, admin setting should be there. You should have your login name And password. Failing that you’d have to reboot from the recovery partition( command/Apple key+ r on startup, then move mouse to top center of screen. You should see os x tools. Go to Terminal and type in ‘resetpassword’ without the quotes. Press the return key. This should get you to the reset password app

john b