Page not found

I created a post and inserted a gallery into the post without any problem. However, when I visit the site and click on one of the photos, I receive a message saying Page Not Found. I figured that I did something wrong and therefore I deleted the entire post and started over from scratch, however, the same thing occurs.

My site is https://www.focusedonimages.com

I am a newbie at this…. somebody please help before I pull all my hair out – lol.