Student or Learner
How does your friend go to school? or How your friend goes to school?
NOT A TEACHER
(1) Many, many, many years ago in England, people would ask something like:
How goes your friend to school?
(2) But the English people then decided to use "do" in questions and the negative.
(3) So today we have to say:
How does your friend go to school?
P.S. But you could say:
I want to know how your friend goes to school. (That is not a direct question. So
you do not have to use "do.")