Question about basic code prefab

Hi! I’m old c++ user, and basic knowlenge on opengl programming. For a commercial game(I will make the game after I finish learning bases of ue4, rest comes with experience) I have decided to use an engine for better collision and features such as fbx support, rangdoll, etc.

So my question here is that I want to start from scratch with basic code prefab, but it has 2 platforms and a table with chairs. I saw them in folders, but “player” is no where to be seen, same goes with his script, how I can see how it works and edit it’s code?