Determine what kind of tour you want to take, then get the appropriate footwear, then the appropriate pedal.
Some tourists cycle seriously most of the day, then stop and spend hours in one place at the end of the day. A pair of cycling shoes and another pair of walking shoes/sandals work well in that case.
Others break up the day with walks, museum tours, etc. Walking shoes work just fine on the right pedal. That's less expensive and less to pack.