I recommend: the following:

Kennedy’s “On Rhetoric” (a translation of Aristotle’s “The Rhetoric”), Longinus’ “On the Sublime,” and the “Rhetorica ad Herennium” paired with the centennial issue of The Quarterly Journal of Speech. If you can’t fit it all in, at least the pieces written by Gunn, Lundberg, Rice, and Chavez are worth reading from QJS as they set up some contemporary views of rhetoric and the stakes of different conceptualizations of rhetoric.

The Routledge Reader in Rhetorical Criticism.” Ott and Dickinson curated this collection in a very coherent way, emphasizing conversational dialectics around which people theorize rhetoric and criticism, and their introductory sections on each dialectic are invaluable. That framing alone makes the collection worthwhile. If you can’t read it all, the part sections, chapters 1-2, 4-12, 13-17, 18, 22, 26-35, 38, 39, and 42 should be a broad enough overview.