First: don't listen to people like Emmy or you will not know how it is in the business.
Photography competition is fiercely competitive, but not impossible. Like Claire said, you need to brand yourself. Your logo, business card, etc should all reflect your photographic style and your personality.
Decide what you want to make a living doing: commercial, portrait/wedding, fashion, stock? If you want to do everything, it's best to do have separate websites and cards. It would be silly to hand over some fancy flowery business card designed for a wedding photog to a prospective client who wants a commercial shoot. And, to add, many people want to know that you only do one thing, and do it very well, rather than doing everything only "okay" (even if you do everything pretty well).
It's hard to say what type pays the best, depends on a combination of your talent, style, how you handle business matters, and most importantly, how well your market yourself.
You make a living by having a different, steady job while you build a portfolio. Then you make a part-time job out of it while you build a client base. Then, once you are getting more in demand for your services, you start full-time. That's how it is for many people. Some people are instantly lucky and make a great living quickly. But most of the time that's not what happens.
You also need to worry about licensing, fees, taxes, accounting software, a lawyer (you are bound to hit someone who's unhappy with the work, even it's amazing), website design, etc.