Hello.
If a child does not want to go to school, it is necessary to find out the reason for this, there may be a lot of them.
Talk to the class teacher, find out in which situations the children insult him, who is the first instigator. Sometimes it can be that the child himself provoke peers. But more often than not, first-graders have a hard time establishing relationships with children: adaptation is taking place, and for everyone it is different.
Contact the school psychologist, if he is in school, let him observe the class and your child, hold a lesson for rallying the team.
If the tantrums continue for any reason, then pay attention to the nervous system, maybe you should consult with a neurologist.
At home, keep a calm environment - do not cry, support the child, rejoice in his slightest success. All the best!