If you want to add a little more culture to your trip, put Gingerbread Museum on your itinerary. Check if guided tours are available or just roam around at your leisure.
You'll be spoiled for sightseeing choice in Stare Miasto. Gingerbread Museum is a great place to start here, but there are loads of other worthwhile spots to experience. Old Town Hall, Old Town Market Square, and Moto Arena Torun are near the museum and will round out your day nicely.