I wouldn't suggest game design or development as a career. It's high risk, low return, very stressful, and often not rewarding. I'd instead recommend pursuing a career in computer science and then doing gamedev on the weekends and evenings.
If you have a game idea, then you must first be able to spec it out on paper—write down everything you want your game to do, step-by-step, through the player interactions from start to finish—and then start Internet-searching the "how-to's". Ask and answer questions like:
We're lucky enough to be living in an age where you don't need an expensive, formal education in something like game development: all the answers are at your fingertips.
If you can't sit down and spec out a game design, you probably don't really want to be a game developer. Being able to plan and execute a design is the most important ability, and no school teaches that. You need your own wherewithal to make it happen.