GMod Player Model Help

So guys, I’m trying to make myself a playermodel from scratch. What I wanted to do with it was just add a “hat” to the head of the model, then make it into an addon. I wasn’t planning no releasing it to the workshop though, I just wanted it for personal use. What I need help in is adding the texture to the hat. I’m editing the SMD’s in Blender and I already added the “hat” I just don’t know what to do next. Keep in mind that the model I have in Blender has no textures. I would like to know what I need to do next and what I should do to add texture. I think I already know how to make it into an add-on.

Thanks in advance.