This is good news! And if you think this is quick you will be very pleased with the speed when it's installed - running from a USB is always much slower.
The desktop you have is the "Unity Desktop". I don't know anyone who likes it, and if you wish you can add an optional desktop: "Classic View" which most people find much more intuitive.
To get your files:
1. When running from the USB, select the file manager from the left-hand menu.
2. At the bottom of the list, select "Other Locations".
3. Select "/dev/sda1"
4. Select "Home"
5. Click on your username.
You now have access to all your files.
It's safest to back up your files using Terminal Commands (
Ctrl+T), and I suggest that you use the "archive" (-a) option. For example:
cp -a Documents <path-to-back-up-USB> ...... as that will preserve the metadata.
You can find the
path-to-USB by
and copying the phrase beginning
/media.... which will be your backup-USB.
Let us know how you get on.
Keith