Higher life forms have risen and fallen many times in our planet's history. The same could be true for other planets. In the big picture, I don't think it matters much whether we're first, or not.
My guess is that it's likely that life has begun on countless worlds in more or less random happenstance. Life here may be old in comparison to life on some other planets, while others may have established ecosystems that predate ours by millions, or even billions of years.
We won't really know the answer to that question until we're able to closely study life on another world. I still hold out hope that we'll find some in our own solar system.
Life has begun? It just starts by itself? Dead things just become alive? LOL