When it comes to Kubernetes it may be helpful to think about Kubernetes in these terms:
Kubernetes has a variety of distributions (e.g. Openshift) and deployment tools throughout the greater ecosystem. Generally speaking it’s the vendors/communities for these distributions and tools which do the testing for any particular operating system for their build and then claim support for it.
Along those lines Openshift has RHEL 8 support because it’s Redhat, and nobody is closer to RHEL than they are. Other tools such as Kops have more recently published betas where they have tested and now claim support for RHEL/CentOS8.
With that context in mind: since you’re a beginner and just getting started you may want to consider deploying Kubernetes to your CentOS machine with a tool like Minikube, which simply requires you to have a local Docker or virtualization platform available (e.g. KVM on CentOS 8).
One of the goals of Minikube is to abstract away your underlying operating system so that you can test and work on Kubernetes without worrying to much about that. I think it could be helpful to start there and get your local cluster up and running before you worry too much yet about how the components work on specific operating systems if your goal is to simply get started using it.
That said say whether you think that is helpful, or if you still feel like there are more questions you need answered. Feel free to join the Kubernetes Slack Channels as well, in case there are smaller questions you have (there’s a #minikube channel there in fact where you could ask around for help if you get stuck).
