Especially just starting out the property management company would need to be licensed. In addition I would want better than average fee structure, and a plan for both marketing and repairs. It is much better if you can mange at least your own rentals as it shows experience. For someone with no RE experience and no experience managing rentals starting a property management company is not the first step if you want to win a customer's business.
@Gerald McCullough if you have no real estate experience or property management experience then absolutely. Otherwise it is like jumping into the deep end of the pool when you don't know how to swim.