Hi MUTigerFan,
I use and have had great experience with IDrive… But, If you want to backup to iCloud, you’re probably going to want to use iCloud Drive. To have space on iCloud for your backup, you’re almost definitely going to have to upgrade your storage plan from the free 5GB if you haven’t already. (50GB- $0.99/month; 200GB- $2.99/month; 2TB- $9.99/month) You can upgrade through one of your Apple devices. You should enable everything under (Mac) Settings>iCloud>iCloud Drive- Options for the most comprehensive backup. This includes the “Desktop and Documents Folders” section. Anything else you’d like to backup you can drag into the iCloud Drive folder in the finder.
I hope this helped, and feel free to ask if you have any more questions.
–Jake