Google calendar

Hello mayorfirecracker, 

Thank you for posting to the Apple Support Communities. 

You can add multiple calendar accounts to the Calendar app on your Mac. With the Calendar application open, click Calendar > Add Account from the top left. Continue through the steps to add and enable your account, the following Apple Support article explains more: Add or delete calendar accounts on Mac. 

If you have a different application that you would like to use with your Calendar account instead, you can save the application shortcut to your Mac’s Dock for easy access. Silly move the application icon to a spot on the Dock to save the location. Find out more here: Use the Dock on Mac. 

All the best!