How do I enable the "extra" stuff in the OpenPublic distribution?
It sounds like you've just installed the wrong profile. At the first step of the installation you get a choice like



Once you choose OpenPublic and follow the installation through, you won't have a vanilla Drupal install any more. For example your home page looks like this:



Don't forget it's still in beta so you're likely to see warnings/notices around the place; I wouldn't recommend using it for a production site yet. It's also pretty sluggish compared to a normal Drupal install so make sure you profile it before deciding whether or not to use it.