Supreme God, lesser gods and alien life - an "empty" argument?

Continuing from my earlier post on the size of the Universe, (see here)

Alien life forms most likely are present in other star systems across the universe. They may or may not have made contact with humans in the past or present though the contact option is more likely. They could possibly be more advanced technologically or at similar level as humans.

How then do we comprehend the notion of God? Where do they exist? Do they co-habit our universe? If they are present in our universe, then who created the universe?

If they are outside our universe in another region, then the sequence of universes can logically be endless or infinite as in a concentric set unless there was a beginning of space and time.

This still raises the question of an eternal all powerful all knowing intelligent Supreme God/Creator beyond space and time. Does the notion of an eternal Supreme God/Creator arise only because we intuitively need a beginning trapped in our material existence?

Imagine for a moment that the Universes and the Supreme God/Creator also does not exist. Then what remains? Instinctively,we might say nothing remains. What does "nothing" mean?

Is “nothing” or “emptiness” the fundamental eternal base of all existence and creation which ancient saints, seers, mystics revered as the Supreme God/Creator? Interesting to note that "nothing" need not be associated with "infinite" as in space or time.

This is extraordinarily difficult to comprehend and define since how can "nothing" have infinite power and energy and be the source of all existence.

Have we really understood and defined the meaning of nothingness, emptiness or sunya???