Man with a Movie Camera (1929)

You don't need to study Shakespeare to be a writer. But you really ought to study Dziga Vertov and Sergei Eisenstein if you want to be a film editor because the two Russian filmmakers really, REALLY understood their craft!
MwaMC is Vertov's most famous and celebrated work. A simple viewing is like a masterclass in editing condensed into just 68 mins. It'll even teach you most of what you need to know about perspective, framing and composition, too.
It's an experimental documentary, so there's no story. It's a series of images captured in four Russian cities showing life as it happens. Contextually there's comparative and contrasting imagery placed close to each other but the meaning is never explicit, it's mutable, distinctly open to interpretation.
I don't have room to detail the groundbreaking techniques used, but many will be clear to see because while it comments on life it also comments on itself.

5 tricksy tripods out of 5

NOTE: Because it's a silent film you'll probably want to find a version with a musical score. I recommend Michael Nyman's. It adds an urgency to Vertov's pure art. I'm not exaggerating when I say it elevates it to the Nth degree.