My actual professional advice: cut portainer out of your learning. Stick to compose as your only docker abstraction and you’ll be a wizard in no time. I have portainer running in my sea of self hosted apps and never use it. If you let some app generate compose files for you, or even just blindly use an app’s example compose file, you’ll never fully understand what’s happening and it’ll make things much more difficult to debug.
4: yes, every container will show up in portainer. 5: I don’t know 6: this is one of the reasons why I personally hate piling layers onto tools. Very often someone else’s opinion does not jive with mine.
Give it time, too. I didn’t discover I’m an absolute fishing fiend until I was 28, and now I’m out with my dad as often as we can. Same with woodworking and building stuff, I picked that all up when I bought a house.
Do I wish I had known this about myself when we lived together? Of course, but I’d be a very different person I suspect and I like who I am.