We are made of stardust
At the start of the universe, the Big Bang created all the hydrogen and helium in the universe. Afterwards, all the heavier atoms were made during a supernova.
This is the dying last stage of a star when the star explodes. Heavier elements like copper and zinc get flung out into space.
We find these elements in our bodies and the food we eat. So that means we are composed of bits of old supernova and cosmic dust.