8 days are enough for you to travel in Shanghai and its nearby cities, such as Suzhou and Hangzhou. Actually, there are not so many places to go in Shanghai besides of the historic streets and modern buildings. But, fun to experience the local life which I do like very much. Suzhou and Hangzhou are noted for their charming natural scenery, for example the classic gardens in Suzhou(https://www.travelchinaguide.com/attraction/jiangsu/suzhou/classic-gardens.htm) and the Hangzhou West Lake(https://www.travelchinaguide.com/attraction/zhejiang/hangzhou/west_lake.htm). The classic Shanghai tour packages(https://www.travelchinaguide.com/package/shanghai.htm) do include these places in.

As for good, you will must have lots of fun. Shanghai & Hangzhou Cuisine and Suzhou snacks do enjoy high fame in the system of Chinese Cuisine(https://www.travelchinaguide.com/intro/cuisine_drink/). Don't forget to purchase some silk products(https://www.travelchinaguide.com/intro/arts/silk.htm) in Suzhou and Chinese Tea(https://www.travelchinaguide.com/intro/cuisine_drink/tea/) in Hangzhou.