The Dam Square. It is a big spacious square for people to hang out and meet. There are street performance might get your attention. It is the meeting point for the free walking day tour too. So it will be really crowded at 1 to 2pm.
There were shopping outlet around it. You might find a shopping plaza inside an old Gothic building. Others than that, H&M which I saw the most shopping bag people are holding.
I do recommend visiting the department store nearby, de Bijenkorf, especially the food court at the top floor.
The department store, de Bijenkorf.