This article explains how to add your Google Calendar events to your Apple Calendar and add individual calendars to iOS. The instructions in this article apply to iOS 11 and later.
How to Sync Google Calendar with Apple Calendar
Here's how to add your Google Calendar events to Apple Calendar and have them sync automatically:
On your iPhone or iPad, go to Settings > Password & Accounts.
Sign in to your Google Account. Tap the Create Account link to create a new Google Account.
