Hi Laurie,
If you will have access to a phone, there is a number you can call that will translate for you if you want to take a taxi. I would also suggest finding and printing out the addresses for the park and wherever you would be rejoining the group in Mandarin ahead of time if you can. Even if you don't plan on taking a taxi, might be good to have in case something doesn't go according to plan. I was only in the city for about two days (not on an
ABD) when I went, but it seems like there was a lot of information available in English around the subway systems and tourist areas. Also, ShangHai has a large expat community and, aside from the taxi drivers, almost every time I tried to talk to someone in Mandarin, they responded in English, "What are you trying to say?"

So chances are, if you did need help I think you'd be able to find someone who speaks English.
Also, I agree that the bund is a must see.
Hope this is helpful.