Copy files from Desktop using command line to a USB

Hello - I can not access to my user GUI KDE session. But I need to recover the files I had in two folders stored in the desktop default folder. Safemode allows me to enter the commad prompt, but I dont know how to navigate to the directory and copy the files to my USB. Please advice.

Log in as user and insert USB medium.
Then you have to figure out which “drive” your medium is (and what file system it uses).
sudo /sbin/fdisk -l tells you which partitions are available
(if you have only one HDD, your USB should have /dev/sdb1)

Then mount your USB to the directory /mnt and copy all files
sudo mount -t vfat /dev/sdb2 /mnt
cp -a ~/Desktop /mnt

and then unmount the USB
sudo umount /dev/sdb1