The Teams button, when clicked, will direct you to the Teams Page.
To create a team, click the plus sign in the right corner.  This will take you to the team setup page for the current Database.  You will need to supply the required information into the correct fields and then add users to the team.  
You can add users one at a time by highlighting their name and then click the single arrow.  If you want to add all the users, click the double arrow and all the users will be applied to the team.  To remove a user from the team, click the single arrow pointing backwards.  To remove the entire list from the team, click the double back arrow.  

Once you have selected all the desired members onto the team.  Click the save button.  You will then be redirected to the Teams Management page.  Here you will see the new team added.  If you wish to edit the Team, click the green edit button.