Our Human Life on other planets

This topic is something i've been thinking of for awhile. Now I know we don't have enough evidence to suggest that our human life is situated on another planet galaxies away however it is very possible. What if there was another planet out there which populated our exact selves as we are today, right now, but either in the past or in the future. Also how long will it take for us to explore further galaxies to find out if such life exists?