Solid advice given by both FM and Viper!
As the FNG, your most important tasks are going to revolve around emptying the trash and doing whatever hard, manual labor there is that must be done(until a newer guy shows up).
You're not to the point Viper said yet, but keep it in mind for when you do get there. You will be expected to keep up with your guys on the line, and to keep them moving. Train them as much as you can, because when it hits the fan, there's no way of guaranteeing that "Doc" is going to be able to be everywhere at once---and, trust me on this one, you're going to want people who know what they're doing if you're the one who needs help. For now, focus on school. What you learn during your AIT is going to serve as the foundation for everything you'll learn later.
And if you'd rather a more colorful version of life through the eyes of a FNG medic, here you go:
Once you reach your assigned duty station, you and the rest of the FNGs will be loaded on to cattle trucks. Packed nut to butt, you'll be taken to your brigade's headquarters. Once there, you and the rest of the fresh meat will be herded on to a stage. Numerous representatives from each battalion will be allowed to "sample the goods." Expect to be jeered, poked, prodded, and inspected. Phrases like "I like that one! The one with the pretty mouth!" or "Get him! He looks like a girl from behind" will be commonly used.
At this point, the brigade CSM will show up and pick out the biggest guy out of the lot to take on a knife fight to the death, just to set an example. naturally, the FNG is going to lose(even if the FNG manages to get a good stab or cut in, it doesn't matter---studies show 100% of all CSMs simply don't require blood to survive anymore). When the fight's over, the CSM will most likely make beef jerky from whatever's left of his opponent.
Once that episode is over, you'll be herded to an arena. It is here that you must compete with the other FNGs in a series of gladiatorial challenges(Bradley-tossing, competitive saline IV drinking, and accessorizing--gotta know how to pick the coolest looking aid bag, you know--just to name a few).
When that's over, you'll finally be given a chance to rest. In the front leaning rest. For approximately 3 days, in hurricane force winds, hail, and raining brimstone. When this is over, your platoon sergeant will finally show up to claim you.
Get some rest at this point, because tomorrow's when the bears come.