The specific error is saying that the file does not exist in your current folder location. So either you have not downloaded hplip, or you are not in the correct folder where you downloaded it. For example if you downloaded it to the folder Downloads then first you have to:
Which Linux distribution or "distro" are you using? (Ubuntu, Slackware, Fedora, Debian, etc.) And what is its version? (7.0, 12.04, 13.37, etc.)
We can probably give you easy instructions to install hplip without using the terminal. You are doing it the hard way!