Hi there!
sp00ky_end Turning on USB Debugging
That's definitely not needed. Are you following the official guide, or a third party one?
Linux Mint isn't explicitly supported, but should theoretically be supported as it's mostly Ubuntu/Debian based (depending on the flavor).
for installation assistance, I would highly recommend jumping into our Matrix rooms, so that we can chat in real time and provide advice. You can find the rooms at:
https://grapheneos.org/contact#community