How to get the calendars on your device:
Press the Add to Google Calendar button in the bottom left corner; Google Calendar opens (log in!).
Select all the calendars you want to add to your Google Account.
Open google.com/calendar/syncselect › and make sure all calendars are checked.
In the calendar app of your choice (e.g., iCloud Calendar), log in with your Google account and let it refresh. The events should appear.