Sorry I missed this question yesterday for you. If you’ll look on the front page of our support site at https://support.organizedthemes.com there is a list of videos. The one that’s labeled “Insert a WordPress Gallery” can show you how to create an image gallery.
For the Foxy theme, you’ll want to set the option for what the gallery links to, to be the file and not the attachment page. Also don’t choose the gallery “format.” That will cause the images you’ve uploaded on that page to be the background which doesn’t sound like what you’re looking for here.