I would wait to see if you like SLS. Many people, as said my the admissions person from my region, either love SLS or don't like it at all. I would open a file whenever the class of 2016 opens, usually late February or March. Open the file, start completing some parts of it, the parts you can. Take the SAT and ACT, do everything you need to for college preparation, continue to get good grades, get leadership positions, etc. Go to SLS and see if you like it to actually want to go to West Point. If you don't, just ask them to close your file and then you won't have to worry about it.