How can I change my desktop background? I've tried everything with no luck Here's a recording of what's going on:
https://i.imgur.com/fBIt1rJ.mp4
This, as you can see, is not ideal. I've also tried it with my own images as well to no avail.
I've tried just about every site on the first page of this Google search.
I have tried

osascript -e 'tell application &quot;Finder&quot; to set desktop picture to POSIX file &quot;/path/to/file.png&quot;' and then killing Dock with killall Dock
deleting ~/Library/Application Support/Dock/desktoppicture.db and killing Dock again with the same command.  After this, I tried to set the desktop picture with sqlite3 ~/Library/Application\ Support/Dock/desktoppicture.db &quot;update data set value = '/path/to/file.png'&quot;; and then killing Dock again.

Still no luck.
Unless you're trying from a user account with restricted permissions, you should be able to change the background image by going to:
System Preferences &gt; Desktop &amp; Screen Saver &gt; Desktop
There, you will have default choices, including those supplied by the system, or Photos, and some folders. You should be able to drop your image into one of the listed folders, or add your own.