The sun will turn into a red giant, then into a white dwarf surrounded by a planetary nebula. This will take billions of years. The white dwarf is basically the ash of a star. It’s a hot glowing remnant that no longer has nuclear fusion and so it’ll just glow for trillions of years slowly losing heat and light until it becomes a cold lump of carbon. The inner solar system will most likely be wiped out during the red giant phase as the sun will expand tremendously in size eventually reaching somewhere between earth and mars’ orbit.