Ist point - You should go for the huge look because then you will acheive the not so huge look quicker.
2. Eat every 3hrs. have protein (eggs, chicken steak etc) with some carbs (rice, pasta, potatoes, whole meal bread) or protein with fats like nuts or natty peanut butter.
3, Drink heaps of milk. 2-3 litres + per day. Thats cheap
4. Stay away from junk where possible. the odd junk meal is ok. You're only 17.
5. Lift heavy, compound exercises 3 times per week. Sqyuats, Deads, Benches, Rows, Power Cleans, Military Presses
Good Luck bloke.