Keep an eye out at Seomun Market — you're likely to discover some treasure or funny trinket in one of its many stalls. After you've found the perfect souvenir, try some fare from one of the nearby food vendors.
This Jung-gu community marketplace is a good place to start your day of sightseeing. There's lots to discover in the vicinity, including Suseongmot Lake, Kyungpook National University, and E-World. Wander around at your leisure at Seomun Market before making tracks to these other fine sights.