Where do I park in Italian towns?

Look for the colour of the lines. Blue lines are paid parking — get a ticket from the nearby machine and put it on your dashboard. White lines are free, and in tourist towns essentially mythical. Yellow lines are reserved for residents or the disabled and will get you towed. Most hill towns have a large paid lot just below or outside the walls, which is where you want to be: it's cheap, it's five minutes' walk from everything, and it's outside the ZTL. Keep coins, though many machines now take cards, and check whether payment is required on Sundays.