I am at Hongqiao Lu, YiLi Lu, Shanghai. Where is the closest station to catch the sightseeing bus and buy a ticket?

The closest station may be the Site of the First National Congress of the Communist Party of China, Xin Tian Di.

You can take the local subway line 10 from Yili Road Station to Xintiandi Station. Then walk to that Site for taking the bus. The bus ticket can be purchased direct on the bus from the driver.