Easiest way to backup my Nextcloud Docker containers and Database with Duplicacy?

Has anyone automated this process for a newbie?

You would start here: Backup — Nextcloud latest Administration Manual latest documentation

Instead of rsync you would directly backup the share with duplicacy but the database exports would need to be done into a separate folder that duplicacy would pick up.

Should not be too hard to adapt duplicacy once you have scripted all above.