What can I and should I recover and how can I do it

[Odense]

I wanted to upgrade my Ubuntu to the latest LTS (Ubuntu 18.04.5 LTS > Ubuntu 20.04.1 LTS) but first got a warning that I would have to remove some ppa's


After I removed the kazam ppa the update was able to start - but stopped again after a while. I rebooted and tried again and it stopped again.
After another reboot get to the gnome classic desktop I prefer but it does not react to the keyboard, the mousepad or the USB mouse I normally use so I cannot even log on.
If I can get most of my own data out first I am OK with formatting the partition and starting again but how do I do this - I tried booting on a live Ubuntu USB stick but the first time I tried this it said that I did not have access to many of the files in my home folder (i tried to copy the whole folder to a USB disk) and when I tried again last night I could not even get the live Ubuntu to see the USB drive.

So how do I accomplish this and what should I copy?

[coffeecat]

Duplicate. Closed.