4-year-olds like schools that are engaging and interesting and where the adults are emotionally attuned to them and find ways to keep them engaged. You sound like you need him to go to school whether this is true of the place you are sending him or not. He might like learning just fine, he just might not like this place.
First it is possible that he is not getting enough sleep at night.
Second, you say he does not like school. He is 4 - so this should be preschool. In other words nothing academic. What does this school do that he does not like? Have you visited the school to see what is going on?