Which terminal should I connect it to for a “C” wire on an american standard AM4A0A30
to answer the question you asked. The "B" terminal is your common. You will definitely need to pull more wires. And YES you need a common for the nest to work. 
 To make your life much simpler, you can add a FAST-STAT Common Maker Thermostat Wire Extender (Adds a Common "C" Connection). hope this helps