I'm new to backing up data should I choose iCloud back up method?

See the article Other ways to back up and restore files - Apple Support

Cloud-based services don't require you to connect an external hard drive to your Mac. For example, iCloudcan automatically store your photos, calendars, contacts, notes, passwords, and more. And it includes iCloud Drive, which can store documents, desktop files, and other files of your choosing. To access those files, you just need to be signed in to iCloud. Other cloud-based services are available from third parties.

You need to turn on iCloud drive and desktops and documents box Use iCloud Drive to store documents on your Mac and iOS devices - Apple Support

More refined way to complete back up of Mac is using a time machine Back up your Mac with Time Machine - Apple Support