You cannot have evening & morning if the earth is not already rotating upon its axis while orbiting an already formed sun.
even according to 'big bang theory' there was a time when the universe was dark, and a time when the mean free path of a photon became long enough for "light" to "exist." -- if current understanding of the way the universe evolved after it's formation is more or less correct, then that same theory predicts that at a specific moment in 'time' the universe became 'transparent' with regard to photons. this means at one point, there was no light, and at the next point - "and there was light."
evening, morning. you got better words to express the idea to a pre-industrial civilization? even today i think if we start talking about Higgs fields and mean free energy, no large % of the world population is going to understand the discussion.
i think there is plenty of room for a universe as old as you want it to be in the Genesis account. i'm not going to argue with God in Glory if it turns out these are literal 24 hour periods either, but iirc the word "day" is not always referencing a 24 hour period in scripture.