Other planets are not going to have the same atmosphere as ours. Chances are we're not going to be able to breath on these planets.
Mathematical nonsense.

There are hundreds of billions of stars in this galaxy alone, with hundreds of billions of galaxies.
Each star has multiple planets.
Eventually, we will find some that support our life.
OK.. I agree with you. But if that planet is 10,000 light years away, could you please enlighten me on how to travel to these planets? If you use a normal mode of transport, then it may take trillions of years.
Distance and speed is the first problem facing, but the future technology maybe have been able solve this problem, to answer that question, we must aware the speed of light