Keep an eye out at Central Market — you're likely to find some treasure or funny trinket among the stalls here. After you've found the perfect souvenir, try some fare from one of the food vendors.
You're spoiled for sightseeing choice in Central Sector. Central Market is a good place to start here, but there are lots of other fine spots to consider. Flamboyant Park, Areião Park, and Flamboyant Mall are close to the community marketplace and will round out your day nicely.