Most of all, love to program. Learn from your co-workers. Don't get too fixed on traditional roles. The computer field is always inventing new things. Try to catch on to a new trend and ride with it.
Computers can be very satisfying and exciting.
Take math courses in high school and every computer course possible. Strong keyboarding skills will be really helpful. Put together your plans for your high school courses, then check them out with the school guidance counsellor. When you complete high school, you will be able to study computers at university or at the college level. I believe that it may be too early in your school career to limit yourself.