1) "There are many benefits including $50 monthly for Azure Subscription. Is this benefit till my Visual Studio subscription expires in 2024.?"
If you purchased Visual Studio Professional you get $50/month in Azure credits.
Cited from https://azure.microsoft.com/en-ca/pricing/member-offers/credit-for-visual-studio-subscribers/
2) "What happen's if montly bill come more than $50 - will I billed or my organization be billed"
With the Azure Credit this is meant for you to sign up and test out the services. You can sign up with a spending limit, and when your credits are gone, you will have to wait until you receive additional credits to continue exploring Azure services.
More information on the $50 Azure Credit can be found at:
https://azure.microsoft.com/en-us/offers/ms-azr-0059p/
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