If the stack Site Name isn't already created in your site, go to Dashboard->Stacks & Blocks and add a new stacked named Site Name. Then simply add a content or image block to that stack with your logo in it.
To setup the home page like the demo, first make sure you activated the 'Home' page type (go to Dashboard -> Pages & Themes and click the 'Inspect' button next to the theme. Then hit the Activate Files button if there are Page Types to be activated. Finally put the home page in edit mode and select the 'Home' page type. Then you'll be able to setup the home page like the demo.
To change the color scheme from the default red & blue to green & brown or orange & teal, simply change the line that says red-blue.css in the screen.css file (located in the theme files at corporateamerica/css/screen.css) to either green-brown.css or orange-teal.css.