In order to delete a space, you must be Owner of that space.
To delete space
Log in with a user account with Owner permissions on the space you want to delete.
Go to the space, and then go to Space Settings.
Scroll to the bottom of the page, and then click Delete this space.
In the warning message that appears, type the space URL name, and then click Delete this project and all the information it.
The system deletes the space and you no longer can view it in the list of spaces.