"Fix" as in, lock it in place, so it doesn't move when I scroll. I can't figure it out. I tried 'Fixed' in a few different places and I tried 'position:absolute;}' which I got from the coding guide thread but nothing works.
What you're looking for is called "background-attachment:fixed", then you'll want to set the background-position (which is top left by default).
I'm afraid that isn't working either.
you've set the background attachment for body, but the background image is on html, so that's where you'll need to set the attachment to fixed.
html {
background: url(https://i.imgur.com/BREphuF.jpg);
background-attachment: fixed}