someone help me to copy files to the flash usb thru terminal commands

hi, im stuck in copying files through the terminal commands i don't know how i can do that, i hope someome help me to do that and thanks y'all geniuses right here

this is my screenshot by the way i tap lsblk to show my usb connected and also i tap the fdisk -l to show the name of my usb (i think):http://s01.geekpic.net/di-DRWN53.jpeg

and this screenshot too showing why i can't copy or move the file to my usb:
http://s01.geekpic.net/di-WZ440F.jpeg

explain to me the full steps please