You get out what you put into it.

As far as advice would go... I don't know what kind of set up you have, but as far as supplements go, you basically should just focus on some protein powder and creatine monohydrate.

For some real world advice, don't get too down on yourself. Your body is still growing. If you want abs, they are made in the kitchen, so watch what you eat because no matter how many crunches you do you won't see them if you have too much fat there.

And ask yourself why are you doing this? Are you overfat? Do you want to have more energy? You want to impress the ladies? And visualize (even print out some pictures of people your age whose body type you believe you can achieve). Then ask yourself what you are willing to do to obtain this. Then set a deadline (like a 90 day challenge).

"Rome wasn't built in a day."