If you have finished a project, then a team or workspace on Calendar may no longer be needed. Here is how you delete a team/workspace.
Once you have signed int to your Calendar account, go to settings located on the bottom left side of your screen with the blue person and cog.
Clicking on that will open your settings menu. Then, choose the workspace option under Admin settings. Only the person who created the team/workspace can delete it.
In the settings for the workspace, you can see the option for deleting it. Click on "Delete Workspace," and it will ask you to confirm your preference to delete. Once you do, the workspace cannot be recovered.