You can use all the services for a Month and after that you will have to convert subscription to pay-as-you-go. In this case, you will be charged based on the service usage.
so my question is that I used azure free trail subscription for learning without any paying?
Yes, you don't have to pay anything when the subscription is Free trial subscription.
You can also explore Azure for student subscription
Reference -
https://azure.microsoft.com/en-in/free/free-account-students-faq/
https://azure.microsoft.com/en-in/free/students/
You can also use Microsoft learn where access is given to portal for specific hands-on task
https://learn.microsoft.com/en-us/learn/
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Please don't forget to Accept Answer and Up-vote if the response helped -- Vaibhav