I’d run it with Docker. The official documentation looks sufficient to get it up and running. I’d add a database backup to the stack as well, and save those backups to a separate machine.

A Pi 4 draws maybe 5W of electricity most of the time. 24/7 operation at 5W will be your cost (approx 44 kWh per year), not including cost of the Pi, your internet connection, and any time you spend on maintenance.