Can't place the slider using php code!

I’m using the free basic theme from themify and trying to insert the slider at the top of the front page.

I’ve added the php code to just below the header, but the slider is off to the left of the page. Can anyone give me any guidance?

Do I need to add some CSS into the stylesheet?

Thanks!

https://www.ads-software.com/extend/plugins/wp-featured-content-slider/