Where to start on the classic Greeks and their cosmology?

Praise Kek

Kek and Keket can be correlated with Erebus, which coincidentally in Greek mythos is also one of the first Gods to come about.

to add onto that, Qerhet and Qerhet can also be correlated with Nyx who, in most versions of the mythos that I am aware of, was the first entity to be born from Chaos/Apeiron/Caligine

Qerh and Qerhet**
sorry, I have a tendency to not read my posts before submitting them

Don't worry, we don't read them either.