...
The game data (art, characters, items, etc) are generated by the build pipeline, this is a set of scripts that you setup. It typically takes 30+ hours to build all the art as there are many things it has to do to get all the art ready for use in the game. Take a look at the guide How to set up the Build Pipeline for information on setting up the pipeline. For information on the layout of the database check out the Database Structure
Setting up a Patch Server
...