An allusion is basically a way to indirectly say something, like "Chocolate was Sarah's Achilles Heel." is allusion, because the phrase "Achilles Heel" means weakness in short, and so its saying that chocolate is Sarah's weakness.
A hyperbole is an exaggeration, like if I said "I am so hungry I could eat a horse!" Obviously I'm not going to actually eat a horse, but its exaggerating how hungry I am