Does it matter if someone meets you in a back alley tonight, clobbers you over the head, steals your wallet, leaves you with severe concussion and broke ?
It matters to me. But that's a very different question than "why are you here?".
Do you think there was a very first instance of natural selection ?
That's hard to say. There may not have been anything that we would recognize as the first instance of natural selection were we witnessing it. Biological boundaries tend to be fuzzy and hard to pin down. There was a time when there was no biological natural selection, there was a time sometime later when natural selection was operating, and research is ongoing. So what?
Or unlucky. According to your view I think it really doesn't matter one way or another. Maybe it was unlucky and the luckier thing would have been for there to be nothing around but dust or cold rocks, or even nothing at all.
I prefer it the way it is, but a near-infinite number of other outcomes would have been possible.
What good is evolution anyway ?
That's way off topic. But it is the best description we have of the history of life, by far, and knowledge in itself has some value. It's foundational to all of biology and a lot of medicine. And more.