Before you fully attempt to get this forum big, ask yourself if you really want to use a free forum hosting service like you are using. You have to remember that you will be forced to stay with them at all times if you want to keep all the members and posts. And if the service decides to shut down, you lose everything and there isn't anything you can do. Think about that long and hard before committing to getting the community established.
Well for starters there's very few posts, and one out of the three members you have is a spambot who's completely littered the general section with junk.
Invite a few friends over and keep posting new content. Eventually people may flock to your site. 🙂