Science Fiction: Stars in the Universe

Li Xingyun, science enthusiast. I have been having a dream recently, a dream of traveling to a prehistoric world. One boring night, Nebula was about to fall asleep. "You are chosen." A voice appeared in Li Xingyun's mind. "I am Garland, the space traveler. Do you want to take on an important task? Your dream was my guide." "Is there any cheat?" "No." "Then how can I live?!" "I believe you." "Believe me? How can I, a mortal, face a saint?" "You can also practice slowly. What's more, you also know some science." "Then it's impossible for me to defeat the immortal cultivators." "There are people in the world over there who have accepted my indirect or direct guidance. When the time comes, you will meet, and there will be people who will accept you as their disciples." "How many have you guided? Are there any saints among them?" "For the first question, no more than 3 questions. For the second question, keep it confidential." "...." Just throw me into this unknown world? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.