It took me a while to work that out too ... the question mark means you're online (it's a question mark because this is linuxquestions, not because something in your profile needs to be fixed!). So at the moment you don't have a question mark.
You get reputation either by people clicking 'Yes' to 'Did you find this post helpful?' on your helpful posts, or by people clicking 'Add to reputation' next to your Tux. Either way, the first step to take is to post lots of helpful answers!