We can't choose if God created us and knows every decision we will make before we have made it. If he created us he set the conditions for what will happen and he knows what will happen so free will is logically impossible under those circumstances.
As for "what happened for us to be here"...
Big bang 14 billion years ago, earth former 4 billion years ago, love started 600m years ago, humans evolved a couple of million years ago. That is the best understanding of the available evidence.
Do you disagree with any of that? If so... Why?