At this time, you can only create an organization when you initially create a Couchbase Capella account.
Refer to Create a Couchbase Capella Account.
To completely delete an organization, you will need to do the following:
This ensures that there are no remaining resources left that can accrue costs in Capella or in your cloud provider account.
Contact Couchbase Capella Support
The Support team will help you settle any remaining billing obligations and then delete your organization for you.