How to run game outside of project folder?

When I do so, it says

There should be “empty graves_data” folder next to the executable

Unity does compiles everything for you. In the file menu is an option “Build Settings” from there you can select the operating system and scenes. Click build and it will make the exe file and data folder (if you select windows standalone).

Build Settings

When you Build to windows Unity creates a data folder and a .exe file.
Both must be in the same place to run the game.