You can create 4 empty pages with just title: Home, News, Portfolio, Contact.
Home and News/Blog are set at Propulsion > Theme Options ; the Contact page is set at Propulsions > Theme Options > Contact .
For portfolio, you need to create a dynamic template and then add it to the portfolio page you've made. There is a tutorial on that subject.
Here is a video on propulsion I made before, though its helpful, I am no longer sure if portfolio covered in it. https://docs.google.com/file/d/0B8hqGBMSfHtKaDJPbDZ5ZFlGQW8/edit?usp=sharing
The framework is close enough in between some of the themes that you can watch a tutorial for a different theme to get an idea how dynamic templates work (since they work same everywhere).