When our Milky Way collides with Andromeda

SSSPPPPPPPAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACCEe!

Noooot quite. You see, when a daddy galaxy and a mommy galaxy love each other, they will come together and make a new galaxy.

Actually no, because there is so much empty space in those galaxies, it would be very unlikely to directly effect us, except with minor changes to earth's orbit. Sure the sun's orbit around the galaxy would change drastically, but that wouldn't really effect us. And the chances of us directly colliding with something is extremely small.

But we would get a really nice night sky

Black holes, usually.

Earth would come to no harm during this

This is not our doing, it's natural and safe