You can delete a space at any time. To do so, visit your personal dashboard, or the dashboard of the organization owning the space. Find your space in the space listing. Then delete the space using the actions menu:
You can delete your organization at any time. To do so, you need to make sure of three things:
You are the owner of the organization
Your organization has no active subscription. It should be on the "Free" plan in the Billing settings.
You have removed every members from the organization.
After that, you can delete your organization by clicking the "Delete" button in the "Danger Zone" of the organization's settings.