Andromeda is going to combine with our galaxy, the Milky Way, in the distant future. In about 4 billion years we’re going to merge, probably having a triple nucleus for a while, while the stars we are familiar with will also form new constellations, but eventually the galactic collision will settle down resulting in a brand new massive elliptical galaxy.
Of course when two galaxies come together you might think there would be a lot of collisions. It seems logical that a whole bunch of little red dwarves, the most common sort of star in any galaxy, would combine to make many more large white suns, like our own. However, the truth is that the space between the stars is so vast that there might be no collisions at all! What will happen is that lots of stars will be flung off into deep space and become wandering solar systems, but the large majority will remain associated and form a large ball of stars.