EDIT: For those who believe the Earth is (12,000?) years old

Let me first state that I know a majority of christians no longer believe this, but I had a good friend of mine once tell me the "Earth isn't millions of years old. Evolution is BS, etc." So in this thread, i'm going to cover her idea of the age of Earth. I am going to assume she believes what I recall being stated in the Bible. Remember though, this is just what I remember. If any of my information is wrong please correct me.

So I know some Christians believe the Earth is, I think, 12,000 years old. If I remember correctly it was 10,000 years before the coming of Christ which was stated?

Anyhow, let's say he created Earth.

This means anything Prehistory did not exist (before 10000BC). Then any artifacts we have before 10000BC must not exist, right? Wrong.

So let's say that 10000BC WAS when the Earth was created.
Our carbon dating has dated things prehistory. With the ideas of Noah's Ark, and other stories of the bible. It is possible a catastrophe of such amounts may have possibly skewed our carbon dating. Possibly, but I do not have enough knowledge to know if conditions of the sort could or could not change the half-life of an item.

I'm not sure if the belief is he created Earth or everything.

So let's say he created EVERYTHING 12,000 years ago.

How could this even be remotely possible? If we have observed objects near 18 billion lightyears away, it must take at least 18 billion light years to reach us.

Say he placed those objects there from the start.

Either way, even if it's only 12,000 years old and God placed materials there, we would not see it yet. So obviously the universe must be at minimum 18 billion years old. If it is, in fact, 12,000 years old, then we have SERIOUSLY messed up our research and light moves too damn fast.

Anybody care to respond to this question?