I agree with what's been said by upnover. It's a lot of hard work, a lot of hard days, and to be frank, a lot of money. I would suggest finding a working student position with a reputable trainer/facility, which may mean relocation. If you're in school, look for a summer intern position and ride as much as possible during fall, winter, and spring. A WS position will teach you the true ropes of the business, while giving you ample riding time and exposure to trainers and clients that come through. You'll also be put on a wide variety of mounts. If you want to be at "the top," wherever that may be, you need to be able to ride any horse you're asked to.
Yardandgroom.com has horse related jobs (including WS positions) if you're interested. Good luck!