I would like to know if there's a way to create an Azure storage container of a specific size, say 20 gb. I know it can be created without any restriction (I think up to 200 TB?), but can it be created with a specific size? What if I need that kind of set up? Like giving a user 20 gb initially, then at a later time increasing it to, say 50? Is that possible?
Like, how do I create that boundary/limitation for a new user that signs up my app?
Not possible with the service by itself. This should be a feature implemented in your app.