I am no doubt going into the Military when I graduate high school which is in 2 years.?

I am no doubt going into the military when I graduate from high school. I really want to go Army and I have done lots of research on all of the branches in the U.S. military. I plan on signing up for the DEP when I turn 17 which is next year. I am not "sick" of it, but I don't want to change my mind about going into the Army. What can I do so that I don't change my mind in the next year? Something motivational?