Is who verb noun or pronoun?

No, 'who' is not a noun, who is a pronoun, an interrogative pronoun and a relative pronoun.

A noun is a Word for a person, place, or thing. A pronounis a Word that takes the place of a noun in a sentence.

An interrogative pronoun is used to ask a question; the pronoun takes the place of the noun that is the answer; for example:

Who is your teacher? Mr. Lincoln is my teacher.

A relative pronoun introduces a relative clause, a clause that 'relates' to the noun that it modifies; for example:

The person who phoned was your teacher.