I am pretty sure we typically parked along Via Manzoni or Via Pozzo la Serra. Look at google maps and zoom in until you see the Comune and post office. There was typically street parking along there. You will know when you are close because you ascend a hill. Maybe the first time, just take the first available spot you see--you will have to walk more, but you will get your bearings. And you can always move the car closer.
You can also search for parking and make a beeline for the parcheggio, but it's really not that bad--it's tiny!