I cannot get dropbox files to show up on my file explorer. I keep trying to download the app but no matter what I do I can only download S mode and I think this is the problem.
Dropbox for S Mode doesn't sync files to a folder in Explorer like the full desktop application does. It's more of a mobile-style client, allowing you to upload and download files in your account as needed.
If you're only able to use Dropbox for S Mode, then you may have a computer running on an ARM-based processor. The full desktop application requires an x86-based processor (Intel, AMD, etc.).