I want to go back to school, but I don't know how to contact the headmaster. ?

I have encountered this problem. You can go to the class teacher to find out the situation first, and then go to the principal after listening to the advice of the class teacher. Of course, giving gifts is inevitable. If you have connections at school, it will be easier to do something. If not, it may take some time to leave school before you know how precious reading is. Reading is not necessarily the only way out, but it must be the best way out. I hope you can cherish this opportunity to study and work.