I have never modded a game before and I would like to get started by creating a new skin for the avenger.
So what do I need to get started?
There are no mod tools offered yet, and there is no way to import any changes to the actual game at the moment. However when the time comes, you will have to use some image editing software (such as Photoshop) to edit the existing texture files of the 3D model. These files will comprise from the Albedo, Roughness, Metal, Emission, and other images. To create a new color scheme you would have to work on the Albedo map (which contains the color info, but for a proper piece, work on the rest of the maps defining material details would be needed.
It gets pretty technical...