Programming a prototype is simple when done slowly. It is common to follow a trial and error strategy while learning a new programming language.
CoffeeScript is designed to be easy to read and program, so it is advisable to look for examples on the internet as you are learning. They will be easy to understand and will teach you new ways to codify your prototypes.
Remember that a prototype should be a fast method of learning as much as possible with minimal effort, and it is better not to go into too complex developments. When developing any functionality in a very detailed way does not contribute anything to your study, opt for developing a functionality that is as simple as possible.
Sometimes, it is better to think of different low-fidelity prototypes that allow you to clarify whether one solution is better than another, looking for clearly differentiated elements...