Open Google Calendar on a computer
Sign in to your Google account
In the left panel, find the calendar you want to share
Hover over the calendar name
Click the three dots next to the calendar
Select Settings and sharing
Scroll to Share with specific people or groups
Click Add people and groups
Enter the email address of the person or group
Choose the permission level
Click Send
To make the calendar public, go to Access permissions for events
Check Make available to public if needed
Choose the public permission level if required
On mobile, open the Google Calendar app
Tap the menu icon
Tap Settings
Select the calendar
Adjust sharing settings if available
Share the calendar link or invite people from the web version if needed