Could you go through the steps of installing Ubuntu on the M.2 drive and then booting from it. I have the EMMC installed with Android.
Hi ,you can check out docs.khadas under Edge section
in your case with android its not easy 
need latest mainline uboot with nvme support which must presented on emmc or sd
but android still used old uboot
Could you explain what uboot is?
uboot is basically the device bootloader, it is what selects the boot medium and boots from it…
think of it like the computer BIOS…