I'm currently trying to make a mod for basically a mountain town based off of McCall, Idaho. Would like some help. First, how do I load files? I will probably post questions here and ask the community for help.
your question is a bit unclear and unspecific if you mean loading objects and such, copy the assets from other maps into your files for your own map, and then modify the materials files to refer to your map as well. will give you the ability in the world editor to load those meshes without texture issues.
take a look here. it's pretty dated, but holds up for the most part, as level creation hasn't changed much. https://wiki.beamng.com/Starting_a_new_map_project.html