Start with yourself and move backwards - who are your parents, grandparents, greatgrandparents. Do you have any older relatives to talk to in the Gerace family? Then start checking out your county archives where you live or wherever your family's American roots are - this will give you info on births, weddings, deaths, and possibly naturalization records which will give you more info as well.
Gerace and Geraci are common in Italy - it will help to know what town your family originated from. Hope that helps. Enjoy the journey