For a professional career in computer engineering, you are eventually going to need a college degree in computer engineering or electrical engineering (not every school has a computer engineering major). You might want to get a masters degree as well, but a bachelor's degree should be sufficient to get you into a great job building computers. That means you're going to need to have EXCELLENT math and science grades in high school. Start studying now to get ahead of the game in math and science. You should definitely get started asap with programming and basic hardware circuitry. You can learn a lot for free on the web by doing courses on Coursera, Codecademy, or even Khan Academy. I would also suggest getting some circuits from a place like sparkfun or another electronics retailer and learning to hack hardware. Build a dog monitor, a door chime, or whatever else strikes your fancy. You can also get copies of MAKE magazine to find new projects to build. Then GET BUILDING!