On your Mac, you can find the files on your Desktop and in your Documents folder in Finder under iCloud.
HOW TO UPDATE YOUR MAC TO 10.12.5 UPDATE
If you do not have the option to add desktop or documents to your iCloud drive, update your Mac to macOS Sierra or later then turn on Desktop and Documents.
On your Macįor Mac's running macOS 10.12 - 10.14 (Sierra, High Sierra, Mojave) You can find your iCloud Drive files in the Files app. Set up iCloud Drive everywhere that you want to access and edit your files. If you have a device that can't update to the latest iOS or macOS, see the minimum system requirements to use iCloud Drive.
HOW TO UPDATE YOUR MAC TO 10.12.5 WINDOWS 7
If you have a Windows PC, update to Windows 7 or later and download iCloud for Windows.
It’s a complete backup solution, but you can use other backup methods as well. Time Machine is the built-in backup feature of your Mac.