Crossword puzzle clue "first class informally"

Class where you might learn about class, informally?

First-class, informally

Allow first-class passengers to board first, say

"Class of" class

Second in his class in West Point's class of 1829

History class: F -- “The professor ignored my attendance record and class participation, judging me entirely on ___”

Class, level or class level

Class within a class