The world is spinning, time is running out, ten thousand years is too long, seize every day, how can I understand the true meaning of this sentence?

"The sky and the earth rotate, and time flies by" means: The earth is constantly rotating, which is objective and does not change based on human consciousness. In other words, time waits for no one, time flies like an arrow, and years fly by. Time will not go back.

“Ten thousand years is too long, seize the day”: If you always think about pushing things back, then nothing will succeed. You must achieve meaning within the limited time of your life. To live your life, you need to do what you think is meaningful now and don't let your life have regrets.

That’s probably what it means.