I've done a little bit of file sharing using Dropbox over the years, but I've gotten tired of paying the $10 monthly fee for a "Pro" account because I was told I had used up too much storage for the free version. I'd now like to instead get rid of some old files, but I've forgotten how the whole thing works. Is there a Dropbox subdirectory somewhere on my machine?
It depends on how you use Dropbox. If have you installed the Dropbox application in your system, then there should be a Dropbox folder where you normally copy the files you wish to upload. If you upload through website, you don't need to look any folder in your system.