1. You may not have sufficient rights to delete anything. The Write User and Read User cannot delete a team, workspace, or tracking page. 

You can read more about permission levels and restrictions in this article: Understanding User Permissions

2. If you use one Workspace/Tracking Page and have not created others, you cannot delete them. If you want to, for example, change the workspace and delete what the previously used, you will first need to create a new workspace, and only then can you delete the previous one. 

3. During the removal of the workspace, a window appears in which you need to enter the title of the workspace and only after that it will be possible to delete it. Be sure to pay attention to the title field and not ignore it. 

These measures are necessary so that users cannot accidentally delete an important workspace and thereby bring down their workflow.

4. To remove a team, you need to contact customer support.