Page is showing codes instead of demo content

A little background: I have customized my site and posted few articles, I am using “grid masonry”  to display post grid, and I set the “latest posts” as my homepage.

I want to put the articles into different buckets separated by category, similar as “News Magazine” demo. I thought there would be an option to let me choose the “latest posts” homepage layout, but I did not find it. So I realized that I must import the demo, and then customize it to get what I want. Is that correct?

And then I imported the news magazine demo, I passed all prerequisitions, and then I imported the demo. However, when I view the page, it displays a full page of codes instead of the content. (See attached the screenshot).

So my questions are:

1) Do I have to import the demo and then customize it to get the layout I need? I just need the homepage layout like http://www.usmama.com/. (It’s Chinese site but you can get what I meant)

2) If I have to import the demo first, how can I set it up correctly?

Thanks!