My site appears in google with a wrong description

Hello, i'm trying to customize my new site, i think that i did everything ok but when i try to found the page in google the description bellow the link of the site appears this: Epic Film Festival » Del 28 al 31 de maig a Barcelona epicfilmfestival.es/‎ Mount Everest is the Earth's highest mountain, with a peak at 8,848 metres above sea level and the 5th tallest mountain measured from the centre of the Earth. i tried to change it but i can't. I hope that someone could explain me that. thank you.