Hi JOAO ROSSI first of all, sorry that you had to make these experiences at the beginning with Azure.
But I want to help you now, to solve your problem.
I understand that you created several Azure subscriptions (free, pay.. ) but none of these works to create an AppServePlan, right?
Could you please check the following things, first:
1.) Is your app service created in the same region as your service plan? It has to be the same region, here
2.) Please check if you have already the necessary permissions to do this action.
More info here: https://learn.microsoft.com/en-us/azure/app-service/app-service-plan-manage
3.) Check if you have reached a specific quota limit in this case. Search for app service here
https://learn.microsoft.com/en-us/azure/quotas/view-quotas
Additionally, you can try this "Quickstart" of Microsoft to deploy an ASP.NET app. Follow the step-by-step guide and in the worst case, tell us later at which point of the guide you got the error (send us the exact error message as well)
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