Get off at tianjin railway station, and then take the 86 to Nanshi Food Street. There is also a snack street on Binjiang Road. The foreign goods market is in Tanggu. You can take the bus or the light rail. If you take the light rail, you can also take the 86 to return, get off at Zhongshan Gate, and then take the light rail for about an hour. The bus should be slower.