In general, Teams for your organization can be added by any Admin in the User management part of the Azavista platform.
To add a team to an event, go to the Event dashboard (at Event level) -> Teams tab. All the teams working on this event will be displayed there. You can add new ones by clicking on the + button, this will open a popup window in which you will be able to select one or more teams to work on the event.
You can remove teams from your event by selecting them in the list, clicking on the three dots in the Actions columns, and selecting the option Unassign.