I'm going to keep this short. The single most useful thing in my Kubernetes journey has been a set of courses on Udemy. Here they are:
I don't have any affiliation. I just want to share the wealth. If you're totally new to Kubernetes, then the CKAD course will be the better choice for you. If you have a little experience with Kubernetes, then the CKA might suit you well, assuming you want to become an administrator and/or know the deep internals of Kubernetes.
And if you have any questions or are stuck on something, please feel free to reach out to me directly or post here in the comments. I'd love to help!