It is estimated that you pressed command+S when you started the computer to enter single-user mode, trying to reset the administrator password. If you want to keep this situation in the command line interface and continue to execute the command, press control+c or semicolon (; ) key, if you want to exit the command line and enter the graphical interface, then press control+c and enter the command.

Exit or

Restart and press enter.

by the way

rm？ There is a space between the commands rm of /var/db/. Applesetup and the following path. If you don't add it, the command will not find an error.

There is also a complete process of resetting the password in single-user mode.

fsck？ -fy；

Mount? -uw？ /;

rm？ /var/db/。 AppleSetupDone

Restart If you are not familiar with the terminal command of the Mac, this method is not recommended to reset the password.