There's a few different ways you can use Amazon Cloud Drive to back up miscellaneous folders. One way is to simply drag and drop the folders you want to backup into your Amazon Cloud Drive folder. Amazon will then automatically upload and backup those folders.
Another way is to use the Amazon Cloud Drive desktop app. With the app installed, you can choose which folders you want to backup and Amazon will automatically upload and backup those folders for you.
You can also use the Amazon Cloud Drive web interface to upload and backup folders. Just login to your account, click the "Upload" button, and select the folders you want to upload and backup.
If you have any other questions about using Amazon Cloud Drive, feel free to ask.