It may be best to copy the commands form this webpage, and paste them one at a time into the terminal .. something went wrong, as the plugins directory never got created.
OK .. lets try again (but with FULL paths), run:
mkdir -p /home/tanya/.mozilla/plugins
If "plugins" is in the output .. carry on, otherwise let me know.
tar -xvf flashplayer-18.104.22.1680-32bit.tar.gz
Now close ALL web browsers .. reopen .. test flash.