Demon Hunter is right on this. As long as All your moves don't have 5PP, you should be fine. Currently, you should have super effective moves against Will, Lance's full team, and part of Koga's and Karen's team along with possibly Bruno with Crobat. And honestly, I would not be worried. You have a 15 level advantage over Will and at LEAST a 10 level advantage over Lance that is sure to grow as you beat each one. Additionally, you probably have found a couple of PP restoring items on the ground in the rare case you run out of PP.
So, don't worry about PP due to your sheer level advantage.