In the Beginning there was H and He. The Early
Universe, just after the Big Bang came up against the
little Berylium problem - He + He 
Be
energy and it not the sort of reaction
that nature likes. In the early Universe, the density and
temperature are dropping rapidly and there is only an instant
when everything is right for the triple-alpha reaction. This
is too short to produce any Carbon or heavier elements.
So, the Universe started with mostly H and a little bit of He.
We already have a way to mix in ``new'' Helium, Carbon and Oxygen. Main-sequence, RGB, HB and AGB stars produce these elements, deep convection mixes some into the envelopes of the AGB stars and then Planetary Nebulae carry these elements into the interstellar medium to be mixed into the next generations of stars.
The rest of the elements up to Iron are cooked up in massive stars and either delivered via stellar winds or, more spectacularly, via Supernova explosions.
SN are like a production and delivery system for the elements.
What about those elements more massive than Fe? Supposedly equilibrium reactions don't work to produce elements on the other side of the binding energy curve beyond Fe.
Michael Bolte