I'm not sure if it's appropriate to call the Aztecs ancient, since my understanding is that they only came about in the 1300s, which, for reference, is around the time of the renaissance in Europe.
hi! not discouraging other responses, but FYI, you can get started in the FAQ
... alternatively, you might enjoy this AskHistorians podcast
This week we look at the role of human sacrifice in Mesoamerican cultures. Tas and idjet read a series of answers from snickeringshadow on the topic.