Ok i have an albino corn snake,how long does it usually take for it to eat or before it will start eating?

ok i just bought an albino corn snake about a week ago, and its still young and we havent fed it because when we got it it was already fed, how long will it take before the snake decides to eat the pinky? and will it not eat it if the pinky is to big? there really arnt any informational sites on this subject, and im feeding it thawed pinkys. so if any one knows let me know.