Thanks for pointing me in the right direction!
A few notes for anyone who stumbles across this in the future:
x86 Debian has a different file structure than a pi.
for an x86 Debian machine. (I'm not sure why your code was injected with all the spaces, but they should also be removed.)
The user should be hyperion (or whatever your local user is) The pi user is not default like on Raspberry units.
There was a typo in the code to start the service:
sudo systemctl starts hyperion.service
sudo systemctl start hyperion.service
So, my final code ended up looking like this:
[Unit] Description=Hyperion ambient light systemd service After=network.target [Service] ExecStart=/usr/bin/hyperiond WorkingDirectory=/usr/share/hyperion/bin User=hyperion TimeoutStopSec=5 KillMode=mixed Restart=on-failure RestartSec=2 [Install] WantedBy=multi-user.target