How do I use my Calendar?

Calendar is the calendar and scheduling component of Outlook that is fully integrated with email, contacts, and other features.

Just as you write in a notebook, you can click any time slot in the Outlook Calendar and start typing. By using the Calendar you can create appointments and events, organize meetings, view group schedules, and much more.

Your Outlook Calendar and Teams Calendar are the same calendar. 

Microsoft have training documents and videos on how to use your Outlook Calendar.

Welcome to your Calendar (Video)

https://support.microsoft.com/en-us/office/welcome-to-your-outlook-calendar-6fb9225d-9f9d-456d-8c81-8437bfcd3ebf?wt.mc_id=otc_outlook  

Introduction to the Outlook Calendar

https://support.microsoft.com/en-us/office/introduction-to-the-outlook-calendar-d94c5203-77c7-48ec-90a5-2e2bc10bd6f8