Hello PT,
Thank you for contacting the Microsoft Q&A community support.
Based on the error in the screenshot above, the user account you are authenticating with seems to be a personal account and doesn't have permission to access the tenant. Also, be sure you are authenticating against against the right tenant
NB: A personal or guest account cannot be used to access the admin.microsoft.com blade.
If you just created the tenant with the email address and you are trying to access the Azure portal via portal.azure.com, check if you are authenticating against the right tenant by using the URL "portal.azure.com/yourtenantid". This will allow you to force the authentication against the tenant. Once you are in the portal, then create an Azure Account from the portal, assign an admin role, and use this account to authenticate to the admin portal. This is only if you are sure the tenant has been successfully created.
Also, I would advise you to sign in using an incognito tab to be sure you are authenticating to the right account.
Let me know if further assistance is required