The story of the creation theory is basically opaque and not too many details were given in the bible pre-earth, however there was a place in the bible that stated that the earth was without void that is it was empty without the existence of anything whether living or non-living so the only thing that existed before God created anything was a deformed earth that had nothing in existence.
However you must know that before Adam and Eve were created God had created other things and he and Eve were the last created which he (God) created on the seventh day before he rested so if you meant whether there was anything or animal or human that was created before the earth began existing then I will definitely say no there wasn't anything created before God started creating anything but if you meant if there was any animal that was created before man then I will tell you that man was actually the last thing God created and then before he created man he had already created animals, flowers and the earth in general was already established.
So to answer your question there was no creation before the existence of earth and the first humans there wasn't even evil spirit or demons because all this were indirectly created by God so God was the only sovereign spirit being that existed from time and it was him who made the existence of the world possible and the bible wrote that it was the word of God that's actually brought about the existence of the earth everything that is inside of it. So there wasn't any creation before God created anything the situation of the earth was just blank and empty and it was the work of God that made the earth to exist so everything nothing existed before God because he was the first ever to exist and it was his existence that brought other existence to life
I assume that Adam and eve were the first humans. It's what's believed. I think there are many sorts of creatures that lived on this earth and definitely there were some that were here when Adam and Eve were here. If not, what would they eat? I guess back then, the creatures weren't the same as we weren't that high tech and even normal dogs would seem to be dangerous. I guess at That time when the first humans were here, the earth was a much more different place as compared to now at the present time.
I think eve and Adam would be different in their appearance as compared to the ones depicted in the pictures at present time. Just about all the creatures that live on earth now would have originated from another species that were here thousands of years ago. At that time, not many animals or creatures were tamed. It would take a lot of years before domestication could take place. Imagine that if we could bring a time machine and bring it to the time when Adam and eve would be expected to live.
@Ijoel, In my opinion, for this question, no Human Being can find the exact answer or reliable answer because, we never know the history is true or not because, we all know that how much manipulation in this world going on. But if i have to guess then i will going to say as, may be some sea creatures would had be there. Stay blessed. 🙂