Can I Switch My MacBook Air Login from Password to PIN?

Unfortunately, you can't set a simple PIN for login on a Mac the way you can on Windows. The security model is different; you'll need to use your password unless you’re using Touch ID with an Apple device that supports it. However, if you want a quicker unlock, consider setting up Touch ID with your Apple Watch or keyboard if you have those options.

You can't actually switch to a PIN like you might think. The fingerprint option is your best bet for fast unlocks, but you will still need to enter your full password the first time you log in or set up the device.