Open Google Calendar
Sign in to your Google account
In the left sidebar, 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 you want to share with
Choose the permission level
Click Send
To make a calendar public, go to Access permissions
Check Make available to public if needed
Select the visibility or permission option
Copy the shareable link if available
Send the link to the people you want to share it with