I recently read the book "Kubernetes: Up & Running" and it was a great resource. Written by Kelsey Hightower it's short and to the point has a bunch of great examples.

As a starter I would get Minikube going on your laptop: https://kubernetes.io/docs/getting-started-guides/minikube/

Then write a small REST app in your favorite language, nothing fancy just something you can easily deploy. Get it running in Docker, and the minikube. Google the problems you have along the way. You will learn a lot by doing this. Now deploy another little app into your minikube cluster and have them start communicating over the clusters network.

This will give you a good start and then you'll know enough to start seeking out more.