There’s some very interesting mathematics proving the existence of an infinite number of universes and therefore every possible worlds exists and at least one must contain life.
This is a bit philosophical but it is very likely that in the galaxies we know about one of them contains life. I don’t believe we will be able to contact them though.
At the moment, scientists think we have explored about 5% of space, so there could be life out there in the other 95% too! The “multiverse” theory that Hayley has mentioned is also really interesting and might support life on other planets too.