I’m just starting with Wheelocks. Obviously, I need to memorize the 20 vocab words in every section. But the book includes these references to words in small bold letters (e.g. discipuli, ioci, etc.) especially toward the end of the chapter. I feel like I shouldn’t move on until I know those words. Am I right? Are they covered later?
Latin words in Wheelock’s outside of exercises proper (including in glosses) are printed in boldface.
You don’t have to set out to memorize the words in the “Latina est gaudium et utilis” sections (that section is a bit of a throwaway and things like “discipuli” are repeated every chapter). As for the glosses in the readings, it’s up to you; they don’t list the entire forms, though, which you’ll need to look up to memorize them.
You’re not expected to learn them but there’s no harm in doing so.
I never did. If you’ve any experience with the Greek course Athenaze it places words below the text. You don’t have to learn these, but you are expected to know them unless it has been several chapters since they were introduced. Swtwentyman gives a good response to this question, and I’m sure that Frederic Wheelock never would’ve intended a student to know the extra words other than what was learned in the chapter vocabulary. We also see this in the Sententiae Antiquae where he gives you words but aren’t expected to memorize them.