I see lights in the sky every night. These lights do not move very fast. I call them stars
If we were living 100 years ago, you'd be right. Every light in the sky would be either a star, comet, or planet.
But nowadays, with 1,000s and 1,000s of satellites in the sky (and more going up every day...Elon Musk and friends are building a satellite network to track every living thing), one cannot be sure what is a star or a human "twinkling thing".
wouldn't they cast shadows on the earth?
I don't know why stars don't cast shadows but this should happen on a flat or globe earth, so it's irrelevant to the flat earth topic.