Was browsing the net trying to find something to occupy my time and found this site that lets you learn ‘ssh’ while solving puzzles. Check Ovethewire.org and start the recommended bandit wargame, and see how far you get. Google becomes a close friend as you try to get through each level. What will happen is you will learn the command line, and the how to use ssh to secure your communications. Hope you have fun and learn a bit of something new.