I started out by setting up a Pi-Hole for my house and learning and failing small to get my head around how Linux worked and how to actually use a command line / SSH / the works.
From there I went to the website https://www.smarthomebeginner.com/ (specifically this guide) which was extremely helpful in understanding the basics of services, networking, DNS, etc. I’d say that if you’re able to get a full setup going with Traefik on Docker, that’s a really good setup for success for self hosting just about anything that can be Dockerized (which is basically anything).
Now I’m able to just read the documentation for a service at hub.docker.com, figure out how I want to customize it for my specific setup (e.g. putting gluetun in front of specific containers, setting up cron jobs to automate some container tasks, and creating a suitable backup) all with my knowledge of how this stuff works which I gained through lots of trial and error with the above guide.
That’s really all there is to it: just diving in, making mistakes, and learning from them until you start to build your knowledge of how stuff works and are comfortable going above and beyond copy and paste.