Since you can't use "Find my iPod," you'll probably have to find it the old fashioned way. In other words, look for it manually. Look in electronics storage drawers/boxes/cupboards, look in the pockets of clothing, look in the family car, look down the back of seats where you sit a lot, look in every room you spend time in and look in your locker (school or workplace) or your study/work desk. It's also helpful to ask people if they've seen it or borrowed it.