No you're not supposed to be a host, you just have to sign up in the actual thread ;) The staff is complete right now, at least for the moment, so you can just join as a sign up. ;) So please just check out that link I sent you, read it and pick your preferred host.
Next Sunday is my lobby, at 1 PM EST. Just send me a message saying "inv bioc" 15 minutes before it starts and I'll invite you. I will also post a new sign up thread today.