Hi Chris,
Thanks for reaching out with your Crio Pro WordPress theme questions! How to change background images is actually a pretty common question, definitely not silly at all.
You can change the background image on your homepage by pulling up the page in the BoldGrid Post and Page Builder page editor. Select the section that holds the image by hovering over the image and using the black “DropTab” that appears to select “Background”.
Using the “background” tab you’ll have control over background images, colors, animations and so on.
I hope this helps! Please let us know if you have any other questions for us.