Apendulum has 622 j of potential energy at the highest point of its swing. how much kinetic energy will it have at the bottom of its swing?

In your example energy is conserved and so the total energy will not change.

Total energy = kinetic energy + potential energy

At the highest point, the pendulum stands still momentarily before it starts moving downwards again.

Total energy = 0J + 622J

At the lowest point, I will assume the potential energy is zero.

Total energy = kinetic energy + 0J = 622J

kinetic energy = 622J

Since the total energy can't change, the potential energy must have been converted to kinetic energy.