Click the Apple menu
Select System Settings
Go to Lock Screen
Set Require password after screen saver begins or display is turned off
Choose a short time or Immediately
Turn on FileVault in Privacy & Security
Set a strong login password
Enable Touch ID if available
Turn on Find My Mac
Use a screen saver with a password prompt
Set automatic screen lock on your MacBook when closed
Lock the screen manually with Control + Command + Q
Keep macOS updated
Use a firmware password on Intel Macs if needed
Avoid sharing your user account or password