It is convenient to taking the tour bus. I think you can take the Jinjiang Sightseeing Bus.The route connects popular sights in the downtown area, including People's Square, Oriental Pearl TV Tower, Yuyuan Garden, and the Bund. All of this attrections are worth seeing.

On the other hand, highly recommend you to take metro as many as possible. Almost every famous spots in downtown area could be reached by metro more quickly.