questions about doors

Hey everyone just bought a 2002 Chevy Trailblazer, I got a great deal on it and only 70k miles. But the only thing is that the front drive door has a weird noise and the guy told me its missing some screws for the door panel so it makes a rumbling sound when I drive.

I have been trying to figure out how I can order a new door panel from it, since I have had no luck finding one, any idea guys?

Factory, salvage yard?

pick and pull place.