It is always amusing to me when I read about inter-galactic travel. Light has a hard enough time traveling from one end of the universe to the other end. Who are we? We are overweight humans struggling with nutrition issues.
Even if we were to somehow manage to speed up enough to reach the nearest galaxy we would zoom right past it. How would you apply the brakes?
Recent observations have shown there are perhaps 40 billion earth like planets just in the Milky Way, our home galaxy. I think that makes it a statistical certainty that life does exist elsewhere besides on Earth. It is possible even intelligent life exists out there.
But the laws of physics tell us human travel across the stars perhaps will not happen. What instead we can hope for is that we get better and better at reading signals that come to us. We could send more probes to the planets and the moons in our solar system. We might even send out robots.
Instead of inter-galactic human travel, I think the goal ought to be an Internet of the Solar System, one to which we keep adding satellites and probes and robots. The Internet of Things populated with robots might even allow us to mine space to quench our thirst for energy and minerals.