The Planet of the Immortal World

What is it like to travel to a planet many times larger than the earth? There are also those magic civilizations, fighting spirit civilizations, card civilizations, and technological civilizations in the universe. There is also the fairyland that occupies tens of billions of light years. Do you think that technological civilization cannot leave a galaxy? A neutron kill can make you die without knowing how, and a planet-level weapon can completely destroy a planet.