I definitely believe we aren't alone in the universe, it's almost impossible for us to be alone in this extremely massive universe. It would be pretty awesome though if we spend some time on mars (a planet untouched by humans) and start discovering signs of previous or current life, that we know for sure did not come from humans or any other earthly species.

And yeah I believe we can evolve mars to fit our needs by using science and technology to create the perfect conditions, we have to actually, earth is a ticking time bomb.