the question: can something come out of nowhere the answer : no , the appearance of the first geometrical structure nullifies the nothing itself which means something doesn't come from nothing but from something in eternal existence . everything that exists is coming into existence by transference of potentia  from  something always in existence.

what would happen if something came out of nowhere ?  

nothing itself ceases to be nothing to be something ,it's contradictory the  nothing would be effective with the ability to bring objects into existence, parmenides said it was not a good idea to talk about  the nothingness, because this could generate an anthological problem ,how are you going to talk about something that doesn't exist.

what existed before the first geometric object ?

if you are working with geometric shapes, everything that exists can be done with just mathematical sums (metamath) physical reality is naturally mathematical. the physical reality it starts from where there was no physical object ?

everything comes from where god is located

there is no physical structure, space, dimension, shape, GOD is not geometry

god has no form

insight into the ideas of the Greek philosopher Parmenides and philosopher aristotle combined synthesis