As I was telling flowrellik, you can find an image of digital camouflage and use the warp tool on Photoshop to make it arc correctly along the hull. The trick is to keep the coloring SUBTLE and make it look random. You can find images of an aztec pattern on the internet, and possibly make it work for your ship. Or you can be crazy like me and make it all from scratch using references- my TMP Enterprise as an example, or my new Excelsior mesh as seen on my sketchfab page.
Either way, your textures are digital. GIMP is free, but I don't know how that program works, possibly similar to Photoshop? Should be easy to learn. Also, much like 3D modeling, you won't get a perfect work of art overnight, so PRACTICE, PRACTICE, PRACTICE. I have dozens of 3D models that have never seen the light of day here- especially my Trade Federation Command ship in the first post in my thread.