If you're using a PC to do the formatting I can't help you because I have used a PC since mine was running DOS 3.0. :-D If you are using a Mac, use Disk Utility:
Erase and reformat a storage device in Disk Utility on Mac - https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/20.0/mac/11.0 - Choose the appropriate system version in the drag-down at the top to get the correct document version.
The "home" view on a Mac is Finder. You can create a folder by going to the file menu and drag down to "create new folder". On a Mac a folder is the same as a directory on a PC. If your files on the flash drive are in a directory you can just drag the entire directory (or folder as it will appear) across to the desired destination on the Mac.
An alternative method is to use the Photos application ( = "program"). I can't provide specifics about that because I don't use it and I run a 10 year old system on this computer so things have probably changed a lot anyway.