1.First of all create new page,set Gallery page template:
2. Copy/paste shortcode below to contentbuilder’s text editor (according to quantity of columns that you want to get) from text file below
https://www.dropbox.com/s/iheh7uyk8uh2lep/Gallery-pages-shortcodes.zip?dl=0
3.Save changes and refresh your site in browser with ctrl+shift+R