I’ve not played prison architect, but from what you’ve described so far it doesn’t sound like you need a complex simulated economy, more like a steady stream of resources that go into a single fund which is then spent on objects in the game.
As others have said, you need to first learn the basics of constructing a game. How to declare, initialise, modify and use a variable, how to declare and call functions and so on. Once you know how a variable works, it becomes much clearer where to store it, when and how it should be used etc.