Potential energy is stored energy due to your position. If comparing yourself to the ground (aka bottom of the hill), the higher you are, the higher the potential energy. Kinetic energy is energy due to motion.
That means at the top of the hill, you have the most potential energy and little/no kinetic energy, depending on if you started moving yet. If you're still at the top of the hill and not moving, you have zero kinetic energy. As you go down the hill, your potential energy decreases as it gets converted to kinetic energy. Once you're at the bottom of the hill, you should have the most kinetic energy and no potential energy because most of that energy was converted to kinetic energy.
Friction would decrease the amount of potential energy converted to kinetic energy because some of that energy would have been lost to friction, which moves in the opposite direction of your direction of motion. That means your speed at the bottom of the hill would be slower than if there was no friction present. That's the reason why you don't go flying off a slide when you get to the bottom, for example!
