Upanishadic concept of creation of universe.

The current model of the origin of the universe assumes that there was  total vacuum/singularly in the beginning(13.8bn yrs ago) and the universe arose from a quantum fluctuation.

In this way, something came out of nothing. At that time it was totally dark since the light had not emerged from vacuum yet.

Vayupurana:

In the beginning, there was nothing in the universe. The Brahman (the divine essence) alone was everywhere

The Brahman was constant and it was the origin of everything that was destined to be in the universe and the universe was shrouded in darkness.

 Nasadiya Sukta (story of creation) also mentions that there was total darkness before creation