To add your Google account information, follow the steps on the screen. Open the 'Google Calendar' from Chrome Apps or Launchpad! Select 'Keep in Dock' to keep the calendar icon in the MacOS Dock (optional) That's it! Your Google Calendar App is now available as a standalone window app from the MacOS Dock and Launchpad.
The informant has bundled your task planning, notes, and calendar in a single app.