The odds of getting in are good as long as you are ready for hard work (that qualification may have already eliminated some of you). Setting up your own kitchen is expensive. Typically, caterers entering the field rent one. A rookie mistake is underpricing your services. It's critical to pay yourself along with the cost of food and any additional labor. If it takes you one day to prepare 500 crab cakes, pay yourself for that day of labor. Avoid catering for free. Part of the price that people pay for catering is the joy of a stress free event. Add the cost of whatever labor or stress it takes to prepare food and oversee servers. However, you can't tack on a million dollars just because you're forming a migraine. Keep it reasonable.
Making too much food is the second most common rookie mistake. After a while, caterers will begin to figure out how much food to purchase. Remember that you do not get paid for food (profit) wasting away in your refrigerator or left with the client. Unless you're charging them $20 per doggy bag, you don't especially want them wading in leftovers.