You must remember that humans invented language - When the first EGG came to be, I'm pretty sure it was not referred to as chicken egg, it is human that attached language identifiers with objects - so we cannot assume that the egg was a chicken egg, but this is the same problem when you ask who created Adam & Eve, so I guess we are all the product of incest So if God created Adam & Eve, who created God, and who created the creator of the creator of the creator ......and you can go on infinitely - so let's assume that both the chicken AND egg existed forever, just like our universe, allegedly You can also ask how did Adam know where to put it - There are things you cannot explain, but more compelling evidence that we are engineered to have acquired reflexes, acquired knowledge, and this evolves with time - take for example the future generation of babies, will all evolve to understand how to build guns and use them, this is why you see a lot of crimes committed by kids............and the latest news in France where a 2 KIDS, 5 and 7 were accused of RAPE........ Humans were engineered with pretty messed up capabilities - or were they ? It could be that they were engineered to be human, with free will, and eventually through "evolution" (more like devolution) humans have become more and more evil pieces of sh**, and this is the result we have today, school shootings, rapists, random murders, serial killers, terrorists and pedophiles. So back to the topic, what came first, the answer is simple, there was no beginning.........things just existed. If you believe in God, then God created everything, and God always existed (try to ponder on that and figure the logic ) If you don't believe in God, then the only thing you can do is assume everything has always been - and again, try to find the logic there, you will never be able to. AND if God was created by aliens, then who the bloody hell created aliens then ? and with this massive infinite space with stars and planets, how come we are alone ? how come we never found other life, I mean statistically in such a big space, you would certainly find other life - so yeah there is more and more compelling evidence that our reality is just a projected simulation of some sorts, but who is running this simulation and who created the infrastructure - good question, just like the chicken and chicken egg thing - Chicken, egg, all objects are a hologram, they are 100% energy, and our human physical brain converts this energy into physical senses, but in reality (if you can call it that) objects do not exist. Only energy.
So eggs and chicken and chicken eggs, same, they always existed, humans gave them names like egg, chicken.