There are three main characters in Star Food.
First, there is Dade. He is the protagonist of the story. I will speak on him more later.
Second, there is Dade's father. He is a practical man. He runs the grocery store (called Star Food), and he does so with dedication. He is a planner and he follows through in whatever he does. Here is a quote that describes him: "He was a short man with direct habits and an understanding of how to get along in the world, and he believed that God rewarded only two things, courtesy and hard work."
Third, there is Dade's mother. She is very different than Dade's father. She is a romantic and a dreamer. She wants Dade to do something great with his life, like Thomas Edison or some other notable person. So she encourages him to gaze into the sky to gain inspiration.
Based on these description, you can see the tension. Dade is in between this mother and his father. This is why the story is called Star Food. He is between two worlds. On one hand he gazes up into the sky (star). On the other hand, he is working at the grocery store (food). This is the conflict. What should Dade do? This conflict is not resolved by the end of the story; this is why the ending troubles many readers. There is no conclusion.