The first thing I looked is a game module for Ashes Without Number and there is one, so that's a good start.
The best resources I know of for Foundry are the
Reddit and the DIscord. You can get a ton of questions answered from those two places.
The main suggestion I have for you is to not go crazy with Modules, because you can quickly add dozens of them! I'd start with the base and then add Dice So Nice and Dice Tray. From there, I'd load the game up and have one of your players test it. Youtube has an excellent series of "getting started with Foundry" videos from the company themselves, but I also like Lunatic Dice, a guy who GMs professionally on Foundry.