Hello Beth Jelich,
Thank you for posting your query here!
I understand that when you use New-AzStorageAccount a Subscription was not found error appears, even though the subscription definitely exists and is accessible.
It is possible that the Microsoft.Storage Resource Provider is not registered for this subscription.
Please try to register the Microsoft.Storage Resource Provider for the selected subscription. This can be done using the Resource providers blade on the Subscription page in the Azure Portal.
Note: Free Trial subscriptions are only valid for 30 days. However, there are some services that are available for free for 12 months. But even to use these 12 months free services, you will need an active subscription.
Reference: https://azure.microsoft.com/en-in/free/free-account-faq
Do let us know if the issue persists or if you have any further queries. I am happy to assist.
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