Eternity

Nothingness not exists as space is infinite place fine-tuned for eternal existence and later life, after certain time of evolution.
Cosmos is eternal as existence is eternal attribute. Anything can exist as something from previous basic form. For sure, the universe has got previous forms while nothingness is unreal.

Never ending principle of those- times present energy; eternal dark energy, might be source of the beginning of forces.
Universe didn't have current form and forces as we know them now, were unified.
Hot dense plasma structures accumulating long time before Big Bang occasions, forming first hot dense plasma matter. After this period all kind of performance has b begun as we know from history of the Universe.

The theory of multiverses directly approves that particular Universes has got eternity.
Space of Universes are infinite together. There is no edge or empty interspaces.
Eternal existence and cycles of Cosmos are inseparable parts.

Nothingness wasn't at the beginning. We can imagine it in our brains and in our world.
But Universe doesn't know nothingness. Do you know imagine Nothingness? Nope. You always imagine dark empty space only.
Universe was always here only in different smaller form with eternal form of energy.