This is a very simple theme. You can use it by simply installing it from dashboard.
There you can find a favicon packaged with the theme. It is under /packages/theme_fictional/themes/fictional directory.
You just need to add this favicon from your dashboard. Go to Dashboard->System & Settings->Bookmark Icons and upload the icon. If you are familier with Photoshop, just open that icon file with photoshop and edit the initial letter of your site name. Then save it. And upload it into the above mentioned path. Believe me, it will look awesome.
You can change the background image from dashboard. The option is called "Fictional" and will be available under Pages & Themes. This page will allow you to set the background image as well as the general color set for the entire theme.