My start was the official kubernetes docs, step by step. Try everything, write it down, make ansible playbooks. Even used some of their interactive training modules, but I quickly had my own cluster up in vagrant so didn't really need the online shell.
Now we have two clusters at work, I have ansible playbooks I'm really happy with that help me manage both our on-prem clusters and my managed LKE with the same playbooks.
I'm completely sold on this container thing. :)