Visual Composer not parsing

I just installed a theme I bought for wordpress and I installed dummy data.
The istructions said I should install the visual composer plugin so I am assuming that is was built that way.
But when I open pages that it came with, it doesn’t parse nicely.
i have 1 page, that when I open it in visual composer the entire page shows up in 1 box that says raw html data.

But when i try to view it in classic mode, all I saw is gibberish letters and numbers

There is another page, that looks like the rows are split properly. But all the boxes say ‘text box’ instead it should be a bannervideo editing box.
when I view it in classic mode , it looks more like visual composer code

[vc_row][vc_column][bannervideo title="Atena Excellence in teaching"  desc="College / University / Campus" 
text1="Take a tour" link1="#" text2="View courses" link2="#" 
play="Play video" image="184" link="https://vimeo.com/20370747" linkmp4="/intro.mp4" linkogv="huploads/2016/01/intro.ogv"]
[/vc_column][/vc_row]

Did I do something wrong when importing dummy data, or is it a problem with my visual composer?

or am I supposed to be using a different rendering plugin