On your computer, open Google Calendar.
In the top left corner, click Create .
Add a description for your event and edit the date and time.
Click on Add Guests to add in participants.
Next, click on Find a Time and pick a time that will work for all invitees
Click Save.
On your computer, go to Gmail and log in to your account.
Open an email message.
At the top, in the line of icons above the email, click More (3 dots) and then Create event.
Google Calendar creates an event, copying the Gmail message title and text, and you can edit the event time, date, and location.
Google Calendar automatically invites people related to the Gmail message. (Tip: To invite more people, on the right under "Guests," enter an email address.)
When you're done, click Save.
You can find more information about the basics of creating a calendar event here.