The best way to learn something is to experience it firsthand. Get a cheap unmanaged vps plan, do not cancel it because of an issue you create, and simply work out the problems on your own. You will learn a lot.
I'm learing towards people who made the switch from reseller to vps. I don't know much about managing servers and getting a managed server is kinda expensive, unmanaged vps hosting can be found from $10 - $30, with decent specifications. so I just what to know how you learned and how long is the learning curve?