Season One, Episode 4, “Rachel’s First Date.”
Otherwise known as, the first time we see Steve Urkel in the show. It’s for a few moments in the opening of the show. Steve comes through the door and the first thing he asks, Carl, naturally is, “Where’s Laura?”
And after Steve teases Carl about all the nasty ingredients in his food, turning him off it and eating it himself, Carl remarks, “Once again, you’ve come between me and the things that I love.”
So those two things: 1.) Steve pining for Laura is already evident in this first appearance and 2.) Carl seems to hint at a prior and apparently annoying relationship with Steve, even though we aren’t yet privy to all of it.
At this point, Steve is relegated to a minor character. It’s not even mentioned here who he is or where he comes from, although it’s presumed he’s a neighbor.
Also, another note: Steve walks right through the door. He didn’t knock. That’ll be a common occurrence, too.
Minor details of note from the previous few episodes: The staircase is there now in the kitchen and Mother Winslow has started a meme (although they didn’t have that vocabulary then) that’ll continue for a bit of, “Way to go Carl,” when Carl messes up.
We also got a pretty forward-thinking second episode, “Two-Income Family.” Harriette loses her job as an elevator operator because they automate the process at the Chicago Chronicle. She’s a bit despondent and then with the encouragement of Carl, goes for a security position at the Chronicle. The boss is a bit skeptical, to say the least, of Harriette’s “management experience.” But then she lays down a verbal smackdown on him, saying as a mother and wife, she managements her family and household every single day.
As one may be familiar with, the 1990s sort of usher in this two-income family notion more firmly than any prior decade, along with the man taking on more roles within the house (although we haven’t seen that from Carl yet, beyond conflict resolution).