Owning a Gas Station

I am thinking about buying a gas station here in NC. It's pretty vague. I have a small restaurant where I have made most of my capital, and met me partner in business. Is there anyone here who has owned or will own a gas station soon ( only buying business, not property). I know there are various licenses I need. Much of the gas stations i have looked at is with brokers i have come in contact in real life. I am not a tech savvy person, but it seems like bizbuysell.com looks like a very good website. When they display cash flow, is it after all expenses?