My recommendation is to look into k3sup and Rancher. I had a lot of trouble trying to install rancher in a docker container and migrating to a cluster after, and k3sup makes it really easy to set up a k3s cluster without having to configure everything manually
You can accomplish the same task with docker swarm, but I figured it would be better to learn something that wasn't abandonware
I haven't dug into the storage side yet since I have a separate NAS, but it will probably be beneficial to set up something like Ceph, GlusterFS, or Longhorn if you don't have one