Energy source for life is the sun, transferred by plants to us as food.
Energy tends to run out, downhill.
Energy is a tricky subject because it can be measured but not seen. Kinetic energy energy in motion like a rolling rock or heat from a burning lump of coal. First law of thermodynamics Energy is neither lost nor gained, but only transformed. Transfer goes from ordered, concentrated chemical bonds between carbons in coal to disordered, dispersed heat and gases. Coal does not spontaneously reform from ashes and hot air.