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Where you may be getting confused is the difference between "perpetual motion" in the sense of the Earth rotating, whether it be around its own axis, around the sun or whatever.
This concept and the "perpetual motion machine" which is a very different concept where the power generation of a system is greater than the energy required to keep it running. It is this second concept that breaks the second law of thermodynamics.
Everything in the universe has a certain amount of motion promotional to the kinetic energy is has. This holds true for anything from atoms to galaxies. The energy pool of one body can affect another body. The moon is moving away from the Earth at some 2-3cm per year, as the moon recedes the Earth spins more slowly. This is known as the conservation of angular momentum, it's the same concept as a dancer having their arms out or in while spinning.
Theoretically you can have perpetual (forever) motion if you have something moving through space and it isn't interacting with anything else. It's energy pool remains constant and isn't changing so it'll continue doing what it's doing.
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