You can delete any Private or Shared Space in which you have been given "Share and modify the space" permission.
How can I delete an empty Private or Shared Space?
If there are no available templates added to a Space, which you want to delete, the complete deletion is very straightforward.
You can delete an empty Space directly from the left-sidebar overview under the Templates menu tab:
Or after opening the Space and clicking on the three small grey dots next to the title on the upper left-hand side:
How can I delete a Space with templates within it?
If you want to delete a Space that includes templates, you have to be aware that all templates will be deleted along with the Space. This may also affect any automations in which you use these templates.
You can initiate the deletion following the same steps as above, but before completing it, you have to accept the warning message about the above. Alternatively, you can decide to keep the Space with the templates within.