How does Twitter work?

Lol, I have clicked on some twitter pages like once every month but I don't get how the whole thing works...

It's fairly simple. You tweet random things or what you are doing and your followers will then see those tweets. You can also follow famous people to see what they are doing. Also you can use hashtags (#) to relate a tweet to something specific or you can use the hashtag to find similar, related tweets.   

Exactly what was said above. It's pretty good if you are a pretty social and active person so you have loads to tweet about and its great to find out what others are up to