There are several ways you can start or schedule a Teams meeting.
Outlook (Desktop and Web version) – Click the calendar section in Outlook, then across the top you should see a button to setup a new Teams Meeting:
Mobile Outlook (iOS and Android) – To schedule a Teams meeting on your mobile device you must use the Outlook app. In the Outlook app,tap the calendar icon, then tap the + sign, scroll down to the Teams Meeting and turn the toggle switch on. Fill out your meeting details and then tap the check mark in the top right of the app.
Teams Calendar – Your Teams calendar automatically syncs with your Outlook calendar. If you want to schedule a meeting right from within Teams you can. Click the calendar button within Teams and click the New Meeting button in the top right hand corner.
Select a range of time within the calendar and Teams will open a scheduling form, where you can give your meeting a title, invite people, and add meeting details. Microsoft Teams also has a Scheduling Assistant you can use to find a time that works for everyone. If you create the invite here, you can actually assign the meeting to certain channels which would invite only the members of that channel.
Meet Now – If you want to start and adhoc meeting and want the quickest way to do so then use the Meet Now button. In your calendar section within the Teams app, in the upper right hand corner you should see the Meet Now button.