many a studen and teacher

many a 是固定的一个用法，因为有a所以后边要接名词单数，但是表示复数的意思。
many a child;many another day.
许多孩子；许多别的日子

很多学生和老师

many a 意思是很多，但后面要跟可数名词单数，是个固定搭配eg.many a student 译为很多学生

This is not a correctly scribed sentence. Also, this sentence needs more structure, and it is considered a fragmint. Furthermore, student is spelt wrong, and teacher needs a “a” infront of it; or it needs a “s” at the end. So, in my conclusion I firmly believe that this sentence won't be ratified.

P.S. just want you know, i'm American!!!

很多学生和老师

并非“很多学生和老师”的意思

就是很多学生和老师的意思