Systemd has a good guide on how to use it https://systemd.io/HOME_DIRECTORY/
And they also have a guide on migrating a traditional user home to this. Do remember to take backups if going this route https://systemd.io/CONVERTING_TO_HOMED/
I personally used the arch wiki when I set it up https://wiki.archlinux.org/title/Systemd-homed
There is not much config.
I think the command I used for my laptop was:
homectl create <name> --storage=luks --shell=/usr/bin/fish --member-of=wheel
https://wiki.archlinux.org/title/Systemd-homed#Creation
Gnome is working on a gui for this, but it will probably be a while until that is out. I feel like it is pretty safe to use the cli for this one.
You can get GPS systems that upload data using a SIM. Only viable if you live somewhere with cheap roaming plans. Last I checked, a local company was selling the hardware (without sim) for 200EUR. The thing I was trying to protect was 120-ish.