Hell Ronald Jackson,
Thank you for posting this in the Microsoft Q&A Community.
From my understanding, you would like to leave an organization you have been added to. Please be informed that you can never be added to an Entra ID organization without an affiliation. Your account has either been created within the Organization or invited to the Organization as a guest.
Since you mentioned that this is part of your az-104 practice, you might want to check if this is a sandbox environment or if you have been provided a test tenant.
However, if this is not the case and you are sure you shouldn't be in the tenant. You can leave the organization on your own.
Follow this link to get more information on how to leave the tenant. https://learn.microsoft.com/en-us/entra/external-id/leave-the-organization
NB: This only happens with an External account. For member accounts created within the tenant, your account must be deleted by the Administrator as you cant leave.
Let me know if further assistance is required.
Babafemi