That's just life and the odds. If nothing else, modeling requires that a person be smart and determined. You also need to be realistic, though. There is zero chance you'll go from a nobody to supermodel fame. But unless you stick with it and pay your dues, you'll never have a chance at realizing your dream.
Life is neither fair nor easy.
This person was lucky, and is not that much more attractive and talented than the next. On the other hand, most people who work hard end up successful. The best place to start looking for jobs is with your friends and family. After hitting up friends and family, you may need to start approaching some of these businesses on your own. Besides, you'll be much more interesting to legitimate agencies if you can demonstrate that you've already had work experience and have been able to find your own jobs.