How you find the calendar depends on if you use your computer or a mobile app, such as your phone or a tablet. If you are on your computer, open your gmail. On the very upper right corner you will see some icons - ?, settings, the 9 dot grid (called app launcher - or Google apps) and maybe your picture if you have one as your Google profile photo. I have a photo there - not sure what would be there otherwise. Just below that on the right side bar you should see an icon with a 31 in a square. This is the calendar. Additionally, the 9 dot grid...click on that and you will see a calendar icon there as well.
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