I like that your trying to start your own company at such a young age. Im 13 aswell and just started a company this year. Its good to get some experience with CPanel, WHM and working with clients before your start your own company. Try volunteering with a small web hosting company and you'll learn alot about how to deal with clients and fix problems fast. I personally never worked for another webhosting company, I just started using CPanel alot and when I found a problem I asked one of my friends who knew about web hosting, and when he told me how to solve the problem I never forgot. Get some nice experience with CPanel, plesk and what ever other CPanel you want to train with. Request some free webspace, and maybe a very small reseller, just to find out what WHM is like and when you think your ready they get a decent sized reseller. Start of small is the best.