Can't change index page

Trying to help a colleague create an event site for his organization. We’ve installed WordPress 3.5 and have total access to the dashboard, etc.

He’s chosen the Responsive theme, added a header image, and played with text, but nothing we do is changing the main page. Nothing we add or edit under posts or pages is doing anything to the main page of the site (located at https://e2conference.com/ or https://e2conference.com/?p=1).

Is there a step I’m missing? I apologize if this question has been asked often, but I can’t seem to identify a thread that addresses this.