To create a new team go to the Teams page and click the "Create Team" button.
Teams are required to have a workflow. You can use an existing workflow, or create a new one. Workflows represent the different phases in which a work item can exist. Notice from the screenshot below that each one of your workflow phases is a colored pill, and exists in one of four workflow categories:
Workflows are only required to have one Active phase and one Completed phase.
The team color is used when displaying at teams work items on the calendar view.
Team board cards can be customized. Select "Custom" if you choose not to use the standard team board card layout.
The Work In Progress (WIP) limit is used with Kanban teams only. It is a way to specify the maximum amount of work that can be worked on at any given time. On Ravetree the WIP limit is the maximum amount of work that can exist in any Active phase of your selected workflow. There isn't anything that will prevent a user from adding more work to a given phase than the specified WIP limit, but it will show you the WIP limit and the current number of work items in each phase.