So ...

As you can see, you have a nice toolbar (similar to the settings in an FTP client) that will allow you to preview, edit, upload, download, and delete files or folders:

All you have to do is to select a given file and any available option or action will be highlighted in the toolbar.

And of course, the folders (and just anything else) will work the same way as they do in a "regular" FTP client:

You can click on any folder to open and view its contents, you can double click on any file to download it, you can drag-and-drop any file from your computer to upload it, etc.