A Team can be created to allow a group of people to get together to collaborate on a short-term project, or it can be used as an ongoing Teams workspace for a Team, Department or working group.
Teams are made up of channels allowing conversations and collaboration with other teammates. Each channel can be dedicated to a specific topic, department, or project. Team members can have chat conversations, store files, work collaboratively and comment on documents and initiate video or audio meetings from within the Team.
See Working in a Team and Channel.
If you do want to work within a Team, you will need to put in a service request with your local IT Support Staff or the Service Desk to get one set up.