Does this mean that there was a generation of stars with only hydrogen that fused into helium, went nova and spread that around?
This new helium went into making new stars which fused hydrogen into helium, and helium into Lithium, then they went bang, ekcetera...
Well, I am no star boffin, but as an interested amateur, I'll try to answer your question. If there is a real star boffin reading this, please feel free to correct me.
As far as I understand all elements up to iron are fused inside stars in a more or less consecutive sequence.
The density and pressure inside of a star is so high, that elements normally couldn't exist. The electrons would be pushed away and the neutrons fuse together. This fusion, however creates energy, which causes s outward pressure. In a star, the inward pressure by gravity and the outward pressure by fusion energy is in a balance. Not all elements fuse under the same conditions, First helium is created by the fusion of Hydrogen atoms, if enough hydrodgen is used up, the pressure in the core goes up until the helium ignites and so on. This process only happens in the star's core and the elements bred there mostly stay there. Until all fuel is used up, that is. What then happens depends mostly on the star's mass. Generally the star is blown apart spectacularly with some of it's core left over as a white dwarf, a neutron star or a stellar black hole.
The gas blown away is still mostly hydrogen, but it is polluted with the elements that were bred in the star's core. It can clump together again to form new stars, planets, whatever.
So we are made of star ash. Literally.