It is extremely difficult to describe energy in magic.Strictly speaking, energy is movement.For instance, if you pick up a stone from the ground,an amount of energy is used by your body.That is "heat energy".If you then drop the stone, the same amount of energy "pulls" the stone to the ground. That's "gravitational" energy. The example given above, of using Tarot cards. Each time you pick up a card, and put it down, you are using energy of different types; heat energy (from your body), kinetic energy (by moving the cards), and gravitational energy (as you place each card). Now, energy can be measured,very often we "feel" it, as heat. So, when dealing cards, Tarot cards or playing cards, it is quite possible to feel the "heat" of energy in the hands and fingers.
I have used dowsing for many years. And again,it is difficult to describe the energy being used; kinetic energy,heat energy, gravitational energy, and magnetic energy (Between the rods and the Earth's magnetic field).
So, you cannot destroy energy, or create it. But you can change it, and "waste" it.(As you lose heat from your body).
Energy is a very complicated subject. To really understand it, you would need to study Thermodynamics. But don't worry about it; energy is in everything; in you and around you; and everything that moves is using energy, whether it is raindrops running down a window pane, or throwing a ball.