How can I find max value and display text next to it in Excel?

If you, for example, got the names in column A and the grades in column B, you could use the MATCHand INDEX functions to return the name of the of the student with the highest grade.

=INDEX(A:A,MATCH(MAX(B:B),B:B,0))

Note that this formula assumes that there is only one maximum grade in the population.