Sorry to say, but you cannot learn easy and fast how to make competitive game environments. At the end there is much to do:

• creating good textures (not only loading photos from the net),
• making them tileable,
• modelling efficient meshes,
• uv-mapping,
• learning about colors and their relations,
• theory of lighting,
• distribution of light and colors,
• faking of real light distribution,
• architecture
• and much more like animation or anatomy

This is an endless field.

I am also a programmer (my job) and an artist (my hobby). And I have to admit that it is more easy to program than to make professional game content.

This is probably the reason why most of the 3dgs users are scripters or programmers and why most projects look like programmer's art.

It took me several years to be able to make models and textures like you can find at our Dexsoft-website. But I learned C++ within a week (I already knew C#, Delphi, Java and others). But even a newby can learn a programming language from scratch within a few weeks.