It remember building a 4 node Beowulf cluster out of discarded compaq desktops and then having no idea what to do with it.
But then 5 years later I was working on them for a living in HPC, but they were no longer called Beowulf Clusters then.
While you are at it, also setup Longhorn for storage. With that solved, you might as well start hosting Gitea and DroneCI on the cluster, plus an extra helm- and docker repo for good measure. And in no time you will have a full modern CI/CD setup to do nothing but updates on! :-)
Seriously, though, you will learn a lot of things in the process and get a bottom up view of current stacks, which is definitely helpful.
Step 2: add advertising
Step 3: make more money than God.