I was not taught the Constitution in high school 60 years ago. It was a good school with a high number of National Merit Scholar finalists. We did cover the Bill of Rights and briefly looked at some of the other aspects. In college I took American Constitutional government which I think may have been a required course. It had a 2 inch thick textbook which we covered from beginning to end.
Note that FDR’s activist justices had started to rewrite the Constitution and its history as early as 1937 when Helvering v. Davis was decided in Congress’s favor. So it would be interesting to see what your government text book had in it.
Also, note that the Constitution’s division of federal and state government powers is not hard to understand — except when you are taught the wrong things about those powers and have to relearn them. I’ve been there.