I have about three documents I want to put in a folder but I only see the option to create a document in a folder and not sort an existing document into a new folder.
Yes, create the new folder. After that, go back to your documents and click on the document you want to move (don't press edit or view just click it). When the UI for the document pops up you'll see a drop down where you can see existing folders. Choose the one you want that document to be assigned to and then thats it.
Thanks, @steeeeeee :) That's right – the dropdown you're looking for is in the top-left of the modal that pops up when you click on a document. It looks like this:
Thank you both!