Hello @Libbycroad, I hope you're well today!
It sounds like you enabled the backup of your Desktop, Documents and Downloads folder when installing the desktop app on your computer.
Can you see the files that you're looking for within the Dropbox folder on your computer?
If you'd like to disable this feature, please follow the steps outlined towards the bottom of this article and then move the files back to their original location from the backup folder in Dropbox.
Keep me posted with any questions!