How does the first stage of the Falcon 9 rocket launch and land at Cape Canaveral, Florida? I was under the impression that its trajectory sends it about 60 miles off the coast. It makes sense to land on a platform at sea. It would have to backtrack a long distance to land near the launch location. Am I missing something or not understanding the SpaceX launch/landing procedure?
Your understanding is correct. The first stage has to come to a halt, then fly back to the Cape.
This is done for flights where there's enough margin (fuel left over after stage separation) to fly back.
If there's less fuel left, they can land on a barge in the ocean. This takes less fuel than flying back.
SpaceX prefers to land the stage on land (recovery is easier, no ships needed), and on many missions they have enough margin to do that. Basically, they made the rocket larger than it needs to be (if you just look at launching the payload) to accommodate the propellant for landing.