Create a new user with parental controls
If you want to set up parental controls for a user, but all the users on your Mac are administrators or sharing-only users, you can create a new user account with parental controls enabled.
Choose Apple menu > System Preferences, then click Parental Controls.
Click the lock icon to unlock it, then enter an administrator name and password (or if your Mac has a Touch Bar, use Touch ID).
Click the Add button .
Click the Age pop-up menu, then choose an age bracket.
This setting determines the default restrictions for the account. For example, each age bracket has age-appropriate rating restrictions for movies, TV shows, and apps from the iTunes Store and App Store. You can set different restrictions after creating the account.
Type a name and password for the new user. An account name is generated automatically. If you want to use a different account name, enter it now—you can’t change it later.
Using a password hint helps the user remember his or her password.
Click Create User.