I like cooking, so I guess I can go with that. It beats getting shot at, that's for sure! I would choose engineer, but while I could potentially possess the knowledge for the role, my skills are extremely lacking.
If I were forced to be a soldier, I'd be a Sniper because it keeps me away from the front lines. Despite having equipment for actual sniping, I'm also a great shot at mid-range with a handgun, though I lack the arm strength to aim one for an extended period; I can point a gun and hit a target quickly, but holding it in front of me would tire me out.
In any case, I'd probably be deemed physically unfit to serve as a soldier anyway because I am extraordinarily weak and I literally can't exercise (I think I have exercise-induced asthma or some breathing disorder and while it may be controlled be medication, an attack at the wrong time will spell death).