Run, then run with someone yelling, then run some more. Then do pushups or pullups depending on branch of service. Then do more pushups or pullups. Then do a lot of swimming if you plan on special...
Crossfit (There is some Crossfit joke about warmups or something). On a more serious note Dynamic stretching. Never tried foam rolling but I hear good things about it.
Getting bigger (muscle or fat wise) actually takes time. There really is no wake up one morning and boom you are fat or boom you are Ronnie Coleman. Check out the nutrition section on this website...
No real reason to put biceps twice a week. If you work on the compound lifts Squat, Bench, Deadlift, Press and eat at a surplus your arms will grow naturally from your body growing. On another note...