Back in 1962, the seller's instructions for my 1st derailleur bike ride: "You have to peddle while you shift, but ease up a bit, then move the lever a little until you feel it shift. If there's noise, move it back & forth til it quiets down"

It was a 5 speed. Just 1 lever, no front DR, so only half as hard to learn I guess.

Then he showed me the DR adjusting screws, "If the shifting gets screwed up, fiddle with these screws until it works again" Don