I'm 17 years old and am about to graduate. Recently I have been given the opportunity to either go into the military or attended a university. I'm wanting to go into the military. My reason is because I want to help protect the us from foreign dangers, but my parents don't see it like that. When I told my parents, they reacted negatively, and right now I feel so degraded that I don't want to do anything. Anyways my question is: Is serving in the military something we shouldn't do, even though we care? How do I get the courage to confront my parents about it and make them understand that it isn't something bad?
You are on the edge of becoming an adult. One aspect of adulthood is that you make your own decisions and deal with the consequences of your choices. Your parents raised you and, hopefully, taught you how to make good choices. They are there to continue to advise you and help where they can, but the decisions are now yours to make. You're going to make some dumb choices and that won't be your parents' fault. You're going to make some good choices too.
Your desire to serve in the military is not wrong. See: Should a Christian serve in the military? Realize that there are both good and bad consequences to the choice. For example, serving God while serving in the military can be difficult if you are not fully determined to be a Christian. See: Do you have advice for a young Christian going into military service?
Basically, if you are going to allow your parents to make you feel bad about doing something that isn't wrong, then you aren't quite ready for adulthood yet. If you are sure of your decision, then all you need to do is join and invite your parents to come to your swearing in ceremony. Let them know that this was your well-considered decision and that you would like their support because you know it will be rough.