Here's a step-by-step walkthrough on how to make a calendar in Google Sheets
1. In the Google Sheets home screen, click on "Template gallery".

2. In the template gallery, select the "Annual Calendar" template.

3. In the first sheet, you will be presented with an annual calendar.

4. You can find monthly calendars for each month in their dedicated sheets.

Congrats! You have successfully created a calendar in Google Sheets!