Calculus is essential if you want to gain a deeper understanding of aerodynamics or indeed anything in engineering. For pilot training, however, you won't necessarily need it, at least not here in Euroland. Should you, however, plan to become a pilot who knows a little bit more about the theory of flight than what was required for the test, or even consider getting an engineering degree, I would strongly recommend you brush up on calculus.
As for the essentials, you will definitely need trigonometry.