You don't have to know how it works in order to use it. I don't know either but I could host services using docker. trust me it's way easier than it seems.
You don't have to... if the project you want to use has a good setup process. Otherwise you'll be scouring Docker docs, GitHub issues, and StackOverflow for years.
I've been using linux on and off for 20 years and docker reignited my interest for running linux. There's plenty of good guides and free courses, if you need help finding one - let me know and I'll send you a YT playlist.
Docker compose is amazing. I don't even know how many things I'm running right now. Hell I'm running things I didn't even use! (I could easily disable or delete them; I'm just lazy)