I just did this the other month. Start with https://join-lemmy.org/docs/en/administration/install_docker.html and https://join-lemmy.org/docs/en/administration/configuration.html. Feel free to message me if you need help. I don't know of any exact step-by-step guide for it though.
I personally have a $5 per month Ubuntu server running my instance that I originally used to do the Linux upskill challenge