Windows Virtual Desktops - Doubts
The question is impossible to answer as it is. It needs a whole case study, proper design and capacity planning.
Starting with the Azure Calculator without exactly knowing what you need is exactly the wrong way to go; especially if, as you said, "this is your first time with Azure".
This is exactly the scenario where you need someone who knows what s/he is doing. Please call someone with actual expertise, either a consultant or a consulting company.
Trying to get something done by trial and error is the worst possible way to approach a project like this.