I've had such thoughts before to such a thing, and well…it all falls down to the fact that we would never be able to know such things. We as humans aren't perfect, nor do we know everything. People have come up with different explanations throughout history as to who created us. I, for one, and being religious, would say that God created the universe. However, others may say that it was some other entity, or say that there is no god at all. But no matter what you believe, none of it can actually be proven as of right now.
So to answer you question, in a way we are all of the above. We create things using out imagination. Stories, movies, videos, creatures, people, personalities, etc. However, depending on what you believe, (and as I said before, I'm religious), you may have been created by some higher diety.
If there is "a first one in reality who was not a part of someone else's ficticious creation", there would be no way for us to know who or what that is, as we are:
a) too low on the chain
b) this entity or god or diety in most cases would be considered, well, godly, and unable to met or seen by normal people without consequences.
Or at least that's how it is in most religions.
Sorry if any of this is confusing or jumbled, I just poured my thoughts out on the idea.