Where students will be affected: United States! (6)
I believe the answer is:
campus
'where students' is the definition.
The answer is a location as well as being a singular noun. This is suggested by the definition.
'will be affected united states' is the wordplay.
'will' says to put letters next to each other (I've seen this in other clues).
'be affected' becomes 'camp' (camp can mean exaggerated or affected).
'united states' becomes 'US' (abbreviation for the United States).
'camp'+'us' is 'CAMPUS'.
Can you help me to learn more?
(Other definitions for campus that I've seen before include "student quarters" , "educational grounds" , "University location" , "Area around a university" , "University buildings and grounds" .)