The phrase "setting off fireworks at the stars" means setting off fireworks at the sky, causing infinite reverie and expressing longing and expectation for the future. It contains the power of hope, constantly pushing people to pursue and strive to realize their dreams. "Everything comes true" means that you can turn your expectations into reality and everything you want can be realized. So "fireworks to the stars, everything comes true" means that people can realize their dreams as long as they have dreams and firm beliefs.