In the 1940s and '50s, what passed for sex education was literally about the birds and bees as metaphors for inception and child birth. The emphasis was on waiting until marriage to engage in sex. There were instructional books with a mostly medical orientation to the information they provided but whether they could be found in the schools is anyone’s guess.
Somehow that generation (and earlier ones) managed to learn enough about sex to engage in it within the context of a society that regarded sex outside of marriage as sinful. By the 1960s, the generation fathered in the wake of World War Two told everyone not to trust anyone over thirty and that sex, drugs and rock’n roll were the only things that really mattered in life.