Is it bad for you to not get the right amount fo sleep?

Refrain from napping after school. Keep yourself active until you are dead tired. Give yourself 8 hours of sleep every night. Depending on certain people, sometimes getting more, or getting less can cause you to be tired. After 8 hours of sleep, you should feel refreshed. And remember, taking a nap DOES NOT make up for the sleep you already lost. You're just setting off your sleep cycle.