A simple tutorial guides you how to use automatic Login feature on Mac computer
1. From the Apple menu choose “System Preferences”
2. Select the “Users & Groups” control panel
3. Click the lock button in the bottom left corner and authenticate with an admin account
4. Click on the “Login Options” button in the bottom left
5. Locate “Automatic login” and choose the username to automatically log in to from the drop-down menu *(see below if feature is disabled or inaccessible)
6. Close out of System Preferences, the Mac will not automatically login to the account selected
If you reboot the Mac, the user selected will now automatically boot up without password entry and with no login or authentication required.