The only way to add a new team is accessing the Teams list and clicking on [+Team] button.
When the button is clicked, you will be able to enter a Name for the Team. It must be a unique name across the account. Once the name is entered, a new team is added successfully to the system shown in Edit mode so that you can update further information such as adding members, projects as well as integrations. The creator will have Owner right to the newly added team.