@Dizzwold for SD card setup in standalone mode, see https://docs.duet3d.com/en/User_manual/RepRapFirmware/SD_card
The DWC files go in the /www folder, not the firmware files. You will need to get the DuetWebControl-SD.zip from the same release as the firmware you are running. Latest v3.4.4: https://github.com/Duet3D/RepRapFirmware/releases/download/3.4.4/DuetWebControl-SD.zip
Unzip this and copy it to the www folder on the SD card.
The firmware binary files go in the /firmware folder. However, so long as you haven’t deleted the firmware from the 6HC, you don’t need them. The Duet runs the same firmware for standalone and SBC, so you shouldn’t need to update the firmware to get it working. Indeed, if you have a Mac, DON’T erase the firmware; flashing firmware on 6HC using bossac on Mac is currently not working. Though you can use an RPi to do it.
Your config files go in the /sys folder.
Once all is in place, follow the Getting connected guide if you can’t automatically connect: https://docs.duet3d.com/en/How_to_guides/Getting_connected/Getting_connected_to_your_Duet
Any further problems, please start a new thread, as this thread is more aimed at firmware flashing on Mac.
Ian