Part of it depends on what state you live in. For example, Texas does not require you to have a license to buy and sell real estate, unless you are representing a third party.
There are many parts of the real estate game.
1. Finding the property, negotiating with the current owner. There are people who are good at this and it is their business. They buy properties, then sell the contract to someone else. These people are called wholesalers.
2. Rehab the property. Whether the property will be resold or rented, it will most likely need repairs and upgrades. These people are usually refereed to as rehabbers or flippers.
3. Sell or rent the property. This is where agents, brokers, or property managers come in.
Some landlords do all of this, some only the parts they like or are good at. Real estate is a relationship game. I would suggest you find a real estate investor's club and join that. You will learn a ton for very little out of pocket, but most importantly, you will start to develop the relationships you need. In our club, we have contractors, hard money lenders, wholesalers, flippers, agents, CPA's, and even a couple of attorneys.