You have no files in your project yet. What are you expecting to see? All you have are your target files and the main game module file (which is just the module that holds the game name). None of them will show up in the c++ part of the editor.
Create a class that is at least based on a UObject (the lowest you can go in the hierarchy). Only then will it show up.
Create a new c++ class via the editor and then recompile your project.