I really like my RPi4 OMV NAS. Flirc case. 2X8TB old Seagate SMR archive drives as ext4 with mergerfs in an external enclosure. It sure was cheap but it handles 16TB just fine. Mainly used for backup snapshots. Sips power by the thimble but it is mostly turned off.
Have you considered backups? If your data is important enough to be encrypted, I assume you don't want to lose it all?
One way to stop being a total noob could be to setup a much more modest and simple backup NAS first. Could be a valuable experience before setting up something more beefy. I even suspect that it might help you save not only your data from being lost but also money from being spent, by allowing you to make more informed decisions.