your IOS/cIOS are fine now after running mauifrogs guide.
it is more a usb setup issue.
I would reccommend to follow the FAT32 loading guide below, as it explains in every detail what you have to do to your drive and how to get the games on it how to set the loader etc etc.
In the end cfg usbloader should be able to see the all games on the drive and you can run them by properly setting the cIOS the loader should use to load the game in the loader settings/options.
good luck for now (if you think about playing out of region games you may also want to check out the FAQ in the softmod basics linked below)