This is almost exactly how I became devops in the first place - the existing guy quit suddenly and I had to pick up the pieces in a hurry. If you're already co

This is almost exactly how I became devops in the first place - the existing guy quit suddenly and I had to pick up the pieces in a hurry. If you're already comfortable with the basics, then focus on one particular element and master it. The other bits will come over time. I recommend Kubernetes as a focus, given your list. Keep in mind at all times that the infrastructure serves the business.