I understand that you can access the value of the size of a player's screen through ScreenGui, however is there another way of accessing a player's FULL screen size in all the values/coordinates.
For example, is there a method of accessing the value of a players FULL screen without using ScreenGui, and also containing the coordinates and axis such as X and Y scale of the player's screen
Also, I don't understand much of the UserInputService
If I wanted to make a script where for every time R was pressed, print("R was pressed") would be printed.
I tried
game:GetService("UserInputService").InputBegan:connect(function() if Enum.Keycode.R then print("R was pressed") end
-- But it doesn't work.
Could you, by chance, give me some tutorials of UserInputService which contains in inputs such as keyboard and mouse inputs. Also, could you give me some tutorials for ContentActionService
These, are the ONLY factors I am having trouble understanding in Roblox wiki.

4 comments
Bookmarking this.
There is a problem. workspace.CurrentCamera.ViewportSize stays fixed. It doesn't originate to the players screen size at all times. It stays fixed. For example, if I have full screen on, and I make it half screen, it only has the value of the full screen measurements and not the half screen, it stays fixed?!
That definitely isn't true? You're probably saving the Vector2 value to a variable - at that point if the ViewportSize updates, your variable will stay the same.
How do you access the viewportsize at all times?