Background on home page

I’m trying to add a background for my home page and I’m not sure I have a Theme that will do that. I click on Background in my Control Panel and have uploaded a photo. I can see it’s been uploaded but I can’t see the picture. https://twoatnight.johnsherry.com/wp-admin/customize.php?return=%2Fwp-admin%2Fthemes.php&autofocus%5Bcontrol%5D=background_image

I’ve gotten a plugin for pictures Photo Gallery but I don’t know how to use it and can’t find a tutorial that explains it. I’m having a hard time finding step by step instruction…

The page I need help with: [log in to see the link]