Who played Lady Bird McPherson in 'Lady Bird'?

Who played Jeff Spicoli in 'Fast Times at Ridgemont High'? Who played Dewey Finn in 'School of Rock'? In which film is Dewey Finn a character? Who played Derek Zoolander in 'Zoolander'? Who played Jo March in 'Little Women'? In which film is Jo March a character? Who played Benoit Blanc in 'Knives Out'? In which film is Benoit Blanc a character?