I'm old enough to remember the world before Current Year, and I didn't encounter any homosexual or "transgender" kids that I know of when I went to school. Homosexuality was odd and a subject of jokes, but not necessarily outright hate. Like "gay" could mean "lame" (as in "that's gay"). And I didn't even know what "transgender" was before around high school. In the schools I went to, the diversity was like
@JackoVerde said: there were a number of kids of different races, like in
The Magic School Bus.
Also when I hadn't yet graduated HS, "gay" wasn't considered family friendly, and it was censored from kid-friendly shows on TV.