Confusion

Now that I've created a blog, I have no idea what to do with it! Do I use it as a personal journal? Do I use it as a way to collect info on something I'm interested in? Do I use it as a place to post major events and have friends/family refer to this, rather than being in the dark about my life? But then again, who really cares? I have to figure out who my audience is before I shape what to do with this thing... I'm definitely confused.