First click Teams on the left side of the app, then click Add team at the bottom of your teams list. Go to the first tile in the Suggested teams view and click Create a team.
From there, you can name your team, add a description, and edit the team's data classification. Once you've done that, you can invite people, groups, or even entire contact groups (formerly known as "distribution lists") to join your team.
Feel free to create more teams—you can have up to 250 teams per account.
Note: Your organization can restrict who can create teams. If you can't create a team or need to turn off team creation, check with your IT admin.
For now, go to your desktop or web app to create a new team.