The reason I always recommend that people read a book before getting into Kubernetes is that there are several things that make a lot more sense once someone takes the time to explain them.
It actually gave me some 90s nostalgia. In order to use a new server technology, I actually needed to sit down with an O'Reilly book.
But what a lot of people need is someone to just explain:
1. The basic idea of setting a desired configuration, and having the cluster try to bring reality into sync with the config.
2. How pods, replica sets, deployments and services fit together, and why Google thought it was a good idea to split them up that way. Also, how ingress fits in with all this.
3. Basic volume management.
4. Other common optional topics, just to get an overview.
The big advantage of a book is that it will try to cover the essential ideas, any why they work the way they do, without getting lost in describing a hundred advanced features you can look up later.
If there's an introductory section on the website that covers just the essentials, that might be enough! But I didn't find one when I was learning.
For trying to get to pro level: Programming Kubernetes. This one is focused on writing code for the k8s ecosystem, but it will teach you a lot of the internals.