LA is a hell of a tough place to try to compete as a photographer... If you can get a good agent to take you on, then for sure that's ideal. But the good ones are picky, of course. Good luck!
Could be really tough, cause the good ones are spoiled for choice. Having said that, if you can create a niche for yourself, who knows what may happen?
Finding a niche is one thing, I feel I am qualified to do that, I have established my own style. My problem has been finding places to show my work and getting it in front of the right people in the right format or situation.
a good way to go about showing your work would be to create a small portfolio and mail it to the art directors of firms you want to work with- so maybe Forbes magazine, Maxim, Horse Monthly... whatever you're aiming at.
If your work is good enough it'll get you noticed and will get your name out there to the people you want to see it.