Point A: Yes, you have been misinformed. It is statistically likely that you went to public school, and the humanists have been busily re-writing history for at least a century to support their statist ideology.
Point B: Although I cannot condone the excesses of the conquistadores, the society they built does not sacrifice thousands of human beings on pyramids any more. It is objectively superior to what it replaced.
I hope this has been helpful!