Welcome Jeff,
passwords aren’t the only thing to read carefully, I spent 24 hours configuring my Mars SBC.
If you use the Debian image provided by MilkV, you will enter the graphical environment from the first start. I saw on GitHub that you have already solved it, the best advice we can leave to those who will follow in our footsteps is to open the terminal and type:
sudo apt remove gparted
At this point you can expand the ext4 partition, the last one in the list, and assign the free space. The second step, to get around the slowness of APT, could be the following:
sudo nano /etc/apt/sources.list
and replace the content with:
deb https://deb.debian.org/debian unstable main
At this point with the command:
sudo apt update && sudo apt full-upgrade
you will get an updated system but you will no longer be able to use the graphical environment. The only way around this is to install the individual programs you need, e.g. if you need a file manager or a text editor:
sudo apt install pcmanfm
or
sudo apt install gedit
Nautilus and other programs require an updated version to install. I hope that a new image will be available soon with the updated kernel as well.
I’ll give you one last piece of advice: if you’re interested in using the graphical environment with Linux, avoid Armbian, it works too slowly.
I apologize for the banal examples, I know I’m responding to an expert user, I hope they help others.
You have to cool the SoC actively, a passive heatsink must be bulky to be effective, with my SBC it works very well inserted into aluminum Raspberry Pi 3B cases.