You will need a high end system all around.
3D modeling takes alot of resources. You will most likely want a Xeon dual CPU system with 16 if not 32 gb of ram and then of course a high end video card.
In high school you should take classes in c, c++, pascal, visual basic or whatever your school offers to get your feet wet in programming. Game writing and game desgining are very different, and if you do not enjoy programming you will most likely not enjoy game designing.