You appear to have 9 users, so "no one" is not an accurate description of the situation.
I fear that a Facebook login is hardly relevant at this stage in the site's development.
There seems remarkably little content on your main site for users to respond to. You can't expect people to start making posts until you tell them a great deal more about the issues you are concerned about, what you stand for, why it is important, why it gets ignored by others. First provide a good amount of content, then you might begin to have a chance to get a response. People will not respond to a vacuum. With no content they'll be nothing for search engines to index and no way for it to appear in anyone's search results. In short, you need to work on content before you can expect users to come and post.
You may not have advertised in appropriate places. For example, if your main promotion has been on Facebook then it is hardly surprising that a number of potential users want a Facebook login in - but then I must ask why you haven't started an appropriate Facebook page, rather than start a site outside Facebook. How have you promoted your forum?
What did you say to the Huffington Post and Youthradio.org? Where are the transcripts?
These are just a few random thoughts in the first two minutes of looking at your site.
Hopefully it will give you some ideas on ways to promote your site and forum.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.