With time, your Unreal Engine 4 Project can occupy huge stacks of storage. Not all of that space is bound to necessary project files. There are a couple of folders you can safely delete to save storage space.
This is helpful for backups when you only want to save the necessary data.
Find your project
The easiest way to find the location of your Unreal Engine project is through the Epic Games Launcher.
Under the Library tab, you see a list of all your Projects.