Changing your lock screen password on a Mac usually refers to changing your user account password. Here's how to do it:
Open System Preferences
Tap the Apple menu ( ) in the top left corner of the screen and select "System Preferences".
Open Users & Groups
In System Preferences, click the People & Groups icon.
Select your user account
In the left pane, select the user account whose password you want to change. Typically, you'll need to select the account you're currently logged into.
Change your password
Click the "Change Password" button in the right pane.
If you're prompted to enter your current password, do so.
Then enter your new password, enter it again to confirm, and you can also enter the answer to the prompt question.
Save your changes
When you're done, click on the "Change Password" button to save the new settings.
Password strength: Make sure your new password is strong enough, preferably with a combination of letters, numbers, and special characters.
Password hints: If you're worried about forgetting your password, you can set up a password hint. But make sure that the prompt doesn't make it easy for others to guess the password.
Memo: If you use iCloud Keychain, you might need to update your iCloud Keychain settings on your other devices after you change your password.
Login items: After you change your password, some automatic sign-in items that require password verification may need to be set up again.
Changing your password is an important step to keep your device and data safe. Make sure to update your passwords regularly and keep them strong and secure.