How to become a Secret Agent? Please read!!?

I really want to be a secret agent when I get older. Not the kind that are like spy's and stuff but like Ada Wong, Leon Kennedy, and Lara Croft. People like that. Normally people start training really early and stuff and I'm 14 and I want to start getting into shape and stuff like that. This isn't just a phase, I've wanted to be a secret agent my whole life... Well not my WHOLE life but for 5 years now (since I was 9) I always used to ask my mom to take me to this spy store across the street from her job where they sold fake tools that spy's use and stuff. I really want to be someone like this when I get older. I know it's dangerous but I REALLY want too. And please don't treat me as a kid, I am very mature for my age everyone tells me so, I don't really see it but apparently everyone else does..... Anyways... this isn't just one of those phases that kids go through I really want to do this, I have my heart set on it. And once I set my heart on something, I don't give up. Please help me get started! Do I exercise a lot to get in shape? Do I take karate or something to do all that cool stuff like Laura Croft? I know I probably sound really immature right now but I don't know what to do or where to start..