We are staying close to the SNIEC, where we can catch Shanghai sightseeing bus?

You can get onto it at Oriental Pearl Tower. Take metro line 2 from Longyang Road Station to Lujiazui Station, Exit 1. Walk north for about 100 yards to the stop at No. 1416, Lujiazui Ring Road.

By the way, the 24h ticket costs CNY30, and the 48h ticket costs CNY 50. Have fun!