There is a ton of great advice in this thread. I hope you are learning a thing or two. I will add a few things from my past experiences.
Working in a kayak shop is a great place to start. I once had the 'wanna be a pro dream'. I started by working in a kayak shop so I could get cheap gear and kayak as much as possible. This lead to meeting all of the who's who of kayaking, which then helped me to make the connections I needed to pursue this path. I eventually was able to get a regional sponsorship with Wave Sport, not because I was the most ripping paddler in the state, but because I was so enthusiastic about the sport and was able to sell the crap out of whatever gear I was using - whether in the shop, or on the water. In fact, I was a horrible creeker and just an expert division playboater when I got my sponsorship, so it definitely has more to do with a company knowing that you are going to increase their companies visibility (and sales) by being an excellent ambassador for their products. Developing your social skills is a must!
Go to kayaking events throughout the nation. Introduce yourself to industry reps and pro's. Ask them if they need any volunteer help setting up booths, or whatever. They might say no at first, but eventually if you are persistent they will start remembering you and accepting your help. The industry is small, so a little persistence will go a long way. Be friendly and respectful. Enthusiasm and passion for the sport and whatever product you may be representing is a must. This type of energy is contagious and helps draw people towards you, the sport, and the products.
Developing your kayaking skills: Travel, travel and travel some more. If you want to become a better paddler you will eventually need to travel - a lot! CO is great for about 4 months of the year.. but eventually you will need to start finding ways to be able to live or travel somewhere in the winter to keep maintaining and developing the skills. You might become the best playboater at your local spot, but you won't become really good until you can be good at every spot that you visit. This goes for river running and creeking as well... the more rapids you see, the more you will be able to understand how your boat will react in different situations. I will never forget when I went out to WA for the first time and got my ass kicked. I was so used to low water CO creeking that when I got to WA where a class 5 creek has 1000 or more CFS in it, I got spanked! Also, when you travel around you will find that you continue to meet and paddle with many of the pro's because they, like you, are usually roaming around looking for the best whitewater. Paddling with people who are better than you will help your skills too. By traveling around I was able to meet and paddle with many of the the top boaters and learned and immense amount from them. It also couldn't hurt to take a stroke clininc or ACA course.
For your age... you should also look into a kayaking school. There are a handful of pro paddlers who went to a semester or two of these types of schools. You get to travel to cool places to paddle and are able to continue your education. They cost money, so you will need to find creative ways to raise or earn money... use Mike Harvey's idea as somewhere to start.
Boyd's advice is sweet! You won't get a sponsorship that pays as you climb your way up the ladder, so you will need to work hard, save money and then travel and live off your savings and/or pick up odd and end jobs to stay afloat financially. (I once sold x-mas trees to boost my travel funds in huntington beach, CA while on my way up to Eugene for the winter.) Or, as somebody else mentioned... I think the Eugene pro paddling crew did it right too. Go to college and paddle a ton. Get good grades in high school right now and try to get some scholarship money and find a college near a good river. I just did the work, save, travel, go broke... rinse and repeat for a few years until I got tired of going broke. At least with the college route you will have something in the end... many good kayaking years, a degree, debt and maybe a job if the economy ever recovers.
It's a hard path to pursue, but in my opinion it is so worth it. You may never make it to the top, but you will definitely have a serious amount of fun while trying.
I hope this helps. Good luck!