My first blog

I have never written a blog before. I have a diary but this is my first blog. I am not sure what to write. It is my blog therefor I can put anything. Do I want to treat it like a diary? Maybe give myself a goal and use the blog as a way to keep track of things? Or am I just doing this for the hell of it. There is so much I want to say. Things that I feel I told my friends or family they would treat me differently. Why do I even need a blog? I have a diary and I am writting a book in which much of my bottled up emotions are poured into so is there even a point to having this blog? I guess not but for now I will make it my little experiment and write all my random useless thoughts onto it.