Thanks for using Circle Flip.
Importing the magazine demo is special because it depends mainly on the posts you have on your website. I guess that what you see isn’t matching the real demo because you don’t have same posts as we have on the demo. The demo here just layouts the main blocks and sections needed. All you will need to do is to customize the posts blocks to show the posts you need (Which posts to show?)
This guide can help you : http://docs.creiden.com/circleflip/content-builder-3/blocks/post-block/
To show a menu and customize the header, please follow this guide so that you can
Let me know if you needed anything further.