Homer’s first time travel was part of the fifth Halloween montage in a segment called “Time and Punishment” (aka “Homer’s Time Travel Nightmare”) where each tiny dinosaur he stomps on alters his own life. The next bit I saw was Professor Frink, who built and used the chronotrike in “Springfield Up,” attempting to tell his young self to choose a different career.
Homer: (to self) Okay, don’t panic! Remember the advice Dad gave you on your wedding day.
Grandpa: (in flashback) If you ever travel back in time, don’t step on anything, because even the slightest change can alter the future in ways you can’t imagine.

Variants

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  1. The Simpsons by Matt Groening (30 October 1994).
    2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . written by Matt Groening