Ok, I flashed an 8GB drive with the image file in the tutorial, then I could see that it created a partition that had a boot.scr and a u-boot.bin file. I put it on the board and it picked it up right to the point where “Flash completed” was displayed.
I turned it off then I plugged the usb with the ubuntu image and turned it on, but now I don’t have HDMI output 
I am going to plug an ethernet cable to see if it actually boots.
I flashed the firmware with
dd if=aml-s805x-ac-spiflash of=/dev/sdc bs=1M status=progress```