How do I ensure a starting position as a linebacker on my football team?

I am a sopre in high school and I am really serious about football. Im shooting to be a starter in the NFL and nothing less of it. I want to be a linebacker. I am 5'8" 195lbs. Almost all muscle. There are 3 players that may possibly be better than me at linebacker and as we all know, there are 3 starting linebackers at a time usually. I need some help,insight,ideas,techniques,football secrets, drills, any kind of help that you can give me because I shoot for nothing less than GREATNESS. I'm also doing this for my mother because I always told her that one day I would get rich by going to the NFL and I would buy her and my Dad anything, She ped away this February. Now, everything I do is dedicated to her. I LOVE YOU MOM!