Making content is fun but it is also a lot of vary hard work and takes a lot of time, in fact most of us who make a lot of content spend most of are time doing that and not running Trainz.

To make most content you need to make a 3D mesh, a 2D texture, UV map the texture to the mesh, export it and then get it to work error free in Trainz. Not everyone can make content, everyone can try but a lot have started to make something only to find out it's a lot harder than it looks, usually they try to start with a steam locomotive, one of the hardest things to make.

To make the 3D mesh you use a 3D CAD program, one of the hardest programs to learn, and what you see in the program is not what Trainz will show. The texture is a lot simpler as you get what you see. UV mapping may be one of the hardest things to do depending on the 3D CAD program used.