The oldest stars in our galaxy are >12 billion years old. Ours is 4.5 billion years old. We obviously don't have a lot (meaning more than 1) of data points here

The oldest stars in our galaxy are >12 billion years old. Ours is 4.5 billion years old. We obviously don't have a lot (meaning more than 1) of data points here but that one data point is that life can evolve in 4 billion years. Whatever the variance is we've had ~3x that for other civilizations to arise in our galaxy alone. Yes we could be "first" (within our cone of spacetime). First of 3? That's possible. First of 1000? Way less likely. There's some BAyesian reasoning about probability spaces you can do here. The very fact that we can't seem to detect anyone else in our galaxy changes the probabilities making it much more likely (but not impossible of course) that we're effectively alone. Also the odds that another civilization evolves over 4B years and reaches spacefaring technology within 100,000 years of us is, statistically speaking, incredibly unlikely. It's way more likely they'll be way ahead of us or way behind us.