You can delete teams from the team details page.
On the Teams page, select the team you want to delete. The team details page displays.
On the team details page, select Delete Team. The Delete team dialog displays.
Select Delete to remove this team from the organization.
This action will remove the team and associated people from the team. If people have been granted access to projects individually, they will still be able to access the project(s) using the permissions assigned to them at the project level.