One thing to keep in mind with a lot of responses is often when someone says “we didn’t learn about x in high school”, what they should be saying is “I didn’t learn about x in high school”. I’ve certainly heard former classmates claiming not to have learned something even though they were sitting next to me when I learned it.

When i was a preteen, we learned about WW2, mainly from a US perspective, and had a fairly large focus on the holocaust, including a visit to a holocaust museum.

As a teen, I had a class on specifically European history. In there, we learned about lot more about the rise of the nazis (though not much on Italian fascists).

Here’s the tl;dr on what I remember learning about then:

WWI ended with the treaty of Versailles which was not a realistic, sustainable peace. We learned about the economic trouble like hyperinflation. We learned about the beer hall putsch, and that it was effectively unpunished. We learned that Hitler then sought power through legal means by allying with a broad range of groups unhappy with the current government. As he rose to power, various elements were purged from the government. Concurrently, political violence from the stormtroopers suppressed minorities and other enemies from organizing against them. This culminated in Hitler being elected chancellor, and then the enabling act gave him ultimate power. In the night of the long knives, all the allied elements in the party were purged. After that was kristallnacht, the remilitarization of the rhineland, annexation of Austria and the sudetenland, and then finally the invasion of Poland.