Shanghai for three days alone - Should I do it?

I'm arriving in China on the 21st of August. I'll be teaching English in Yangzhou, a city an hour away from Shanghai. The school is supposed to pick up the teachers arriving in the country on 24th, so that means I have an opportunity to stay in Shanghai for three days. Questions:

1) Will it be safe?
2) Is there a language barrier? (I don't speak that much Chinese yet)
3) Is it expensive?

Thanks so much!