Good luck. Also check out my post here: ZFS RAID Config for old disks
where I explain a few stuff I learned around when dealing with my Proxmox box. And check out the links in the OP to Sarge’s explanations to the other, older topic, he does a great job explaining lots of ZFS stuff. There’s lots of things to learn. TrueNAS Core or Proxmox should be fine for what you need I think.