The Earth supports the only known life in the universe, all of it depending heavily on the presence of liquid water to facilitate chemical reactions. While single-celled life has existed almost as long as Earth itself, it took roughly three billion years for multicellular life to form. Human life has existed for less than one-10 thousandth of the age of Earth.
All of this suggests that life might be common on planets that support liquid water, but it might be uncommon to find life that studies the universe and seeks to travel through space. To find extraterrestrial life, it might be necessary for us to travel to it.
However, the vastness of space, coupled with the impossibility of traveling or communicating faster than the speed of light, places practical limits on how far we can roam.