Problem with SEO description

Hello!
So i made a site few days ago and i have a problem with SEO description. I downloaded ready theme from internet which should allow me to change the description, but unfortunately on google search under the name of my site it just shows my newest post...
Any help?

Here's link to the site

http://www.gazetagraczy.pl/

Thanks from above!

Hi!

Have you entered any site description on page HellFire --> Seo in the dashboard of your website?