Hello there,
I recently started my journey again and I have some documents/files in my game that I would rather keep private, hence this question.
i would appreciate it if anyone would have some information about this to read, I couldn’t find anything yet in the official documentation.
Thank you
Hey there @CarbonTD! Welcome to the community! As long as you don’t put your files up on Github or any other source control, no one can see any of your work, it’s all saved locally.
Thank you very much 
is there any official documentation that supports this?
Hmmm that’s a tricky one, it’s usually implied that the software doesn’t send anything back besides the account information (as such falls under the GDPR) for legality. Though the engine source code is open, available, and unabridged! The launcher only has folder locations, Uproject data, and takes the thumbnails from the project folder to display normally, though if you don’t even want the launcher to be aware of anything you can also build unreal straight from the source, then it’s even more untethered.