Nearest confirmed extrasolar planet :
Epsilon Eridani b, distance: 10,5 light years or 99.337.669.962.098,4 km
Fastest space flight so far:
The Apollo 10 crew, speed: 39.896 km/h
Using this, we could reach Epsilon Eridani b (which might be uninhabitable) after 284.237 Earth years.
Even if we find extrasolar planets around the nearest star
Proxima Centauri, which is 'only' 4,2 light years away, it would still take us 113.695 Earth years.
We need to be able travel quite a bit faster for it to be feasible........or we'd be better off starting with Mars. At it's closest, it's only around a 100 million km's away - easily done in a few years time with slower shuttles, or in a 100 days if using the Apollo 10 speed....
I hope to live to see a Mars colony. Perhaps even to inhabit one. Is it insane?