There's a Wikipedia article on this: https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_W

There's a Wikipedia article on this: https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_co... but the gist is that Galaxies are mostly empty space; so even though the massive black holes in the center will eventually collide, most of the stars/planets/etc. will remain in unfazed. Also in about 4-5 billion years, the sun is slated to reach the end of its life, at which point it will grow big and hot enough to destroy all life on earth (and possibly earth itself). This seems like it's more of an issue to be worried about. See also: https://en.wikipedia.org/wiki/Future_of_Earth https://en.wikipedia.org/wiki/Future_of_Earth, https://en.wikipedia.org/wiki/Timeline_of_the_far_future https://en.wikipedia.org/wiki/Timeline_of_the_far_future