We are :P
Tiff wrote a post here on self hosting it: https://reddthat.com/post/19103
Also nearly everyone is using docker for Lemmy and as long as unraid lets you run docker commands you should be fine.
Docker compose is (now) part of docker. It's a way to describe all the containers you want, and then docker goes and does it. You should 100% learn docker compose, and Lemmy already has a compose file in their repo. So you should be able to copy paste and say docker compose up -d