If you have an old laptop sitting around, put a linux server or NAS distro on it and start tinkering. There can be a lot of analysis paralysis with this stuff. Sometimes it’s best to just try and fail and learn and try again. More likely you’ll try and succeed and realize other wants and needs and redo it a year later. I think that’s why it makes for a great hobby. Lots to learn and improve upon.
Start small, on your local network. Maybe something like paperless-ngx: not very demanding of resources, and (I assume) easy to backup/migrate. You could see about putting it on truenas to get a sense of what that process is like. I personally like to keep a nas and server separate, then mount the nas on the server.
I’ve found owncloud a bit complex and prefer dedicated solutions. For the seas, servarr apps come up a lot. Paperless ngx for docs. Immich (or ente) for photos/vid. If you’re just starting out, installing on linux and/or using docker is going to be your shortest path to success. proxmox or other VMs can complicate things if you’re not familiar.
Team 13-month-calendar assemble!
I haven’t done enough digging on metric time, but if it’s implemented as a UTC/global time I can get behind that. I’m sick of timezones and DST.