Good thought. Many scientists have already thought about it. Its called terraforming.

Mars has many problems thst need to be solved for humans to live there.

1. Atmosphere. Somehow, you need oxygen, and filler gas nitrogen and some carbon there. You can get these vis comets in theory but we dont even have a way to control comets or steer them into mars.

2. Soil. Mars has no soil. The ground in mars is self sterilizing. Its toxic to bacteria and plants. We would need to remove or change the surface. Also bring soil from earth. The dust is also sharp. You dont want to breathe in that or you are dead.

3. Magnetosphere. No protection from cosmic rays. In theory a thick atmosphere would protect people. But scientists are not 100% sure about this one.

4. Gravity. Gravity on mars is pretty bad. It might not be possible for humans to live with such low gravity.

5.Time. Terrsforming mars could take thousands if not millions of years. Its not worth it imho.

In my opinion, it would be smarter to use geo engineering or space mirrors to decrease sunlight hitting earth. This could solve our problem with the sun for billions of years and extend earths life until the red giant phase of the sun.

In the red gisnt phase, in theory, we could extend the orbit of earth away from the sun toeards jupiter.

But after that, just a bit of shade would solve the red gisnt phase of the sun aswell.

But we wouldnt have a way to prevent the death of the sun. But in theory, removing helium from the sun could extend its life.

But who knows. I enjoy discussions about space.