Feels dumb to say, but some people are dumb and need it to be said. Dialogue is not conversation. It's the impression of conversation, but it's characterizing and driving the story forward.
The next thing to understand is that characters are not people. They are impressions of people. And their relationship should be inferred in what they're saying.
Get over being a turbo-autist so you can float and learn how to swim. And the first thing you got to do is get in the water. You'd be surprise how many people miss that step. They write out character dossiers full of information like blood type and family trees. But then they fall prey to "confirmation bias" and fail to even mention a character by name when they're first introduced.
Or like, as the author, you might know that 2 characters are childhood friends. But the readers can't know that unless the dialogue draws that out. "remember when we where kids?"
That's indirect characterization right there. Retard pitfall #2. Show; Don't tell. It's not automatically "telling" just because a character spoke it. A character asking another character to remember suggests an existing relationship. It's not the same thing as a narrator explicitly stating how many years they've know each other, lived in the same apartment complex, whatever
The point of the Show;Don't Tell mantra is to elicit reader engagement. The readers are connecting the dots and synthesizing meaning on their own. Don't chew their food for them.
So once you can swim the next lesson is to hold your breath and dive. The scope of the story might not be that deep. But you need to figure out what the dialogue is filling. The subtext. On the surface, the characters might just be making arrangements. But underneath all that is important context. Like, a teacher doesn't give "extra credit" to all his students. The dialogue then expresses an understanding of their reality. Otherwise you just have floating heads in a void.