When I started up my first computer I was very excited. I unpacked it from its box. Set it up on a table and turned it on. As the screen flickered into life my excitement mounted. Watching it boot up with some unknown messages scrolling up the screen my excitement became almost unbearable. Then there was a beep and a black screen with a flashing green block. My excitement flashed over into puzzlement. What am I supposed to do? Welcome to the command line!