If you aren’t already familiarized with the Docker Engine - you can use Play With Docker to fiddle around, spin up a container or two using the docker run command, once you get comfortable with the command structure you can move into Docker Compose which makes handling multiple containers easy using .yml files.
Once you’re comfortable with compose I suggest working into Reverse Proxying with something like SWAG or Traefik which let you put an domain behind the IP, ssl certificates and offer plugins that give you more control on how requests are handled.
There really is no “guide for dummies” here, you’ve got to rely on the documentation provided by these services.
“Technically” my jellyfin is exposed to the internet however, I have Fail2Ban setup blocking every public IP and only whitelisting IP’s that I’ve verified.
I use GeoBlock for the services I want exposed to the internet however, I should also setup Authelia or something along those lines for further verification.
Reverse proxy is Traefik.