I use RHEL/Rocky 8 for all my home server stuff mostly because i like my home server stuff boring and stable.
Since you were considering TrueNAS, maybe consider something like Debian/Ubuntu + CasaOS. That will give you a good base and webui to work with.
It’s not going to be a lean as it could be but it should give you enough guard rails and hand holding to get you started. Then you can figure out the rest of your needs from there. If you don’t like it you can always wipe it and try again with something else.
I’d stay away from the TrueNAS, Unraid, Proxmox, etc. mostly due to your hardware and that it’s your first home server.
They’re not bad at all, but a lot of the stuff is abstracted from you and since you’re more than likely going to want to tinker with it having a standardized base install with a distro that has a lot of documentation is going to be very helpful.