We are spending 4 days in Beijing and 3 days in Shanghai. We have no Manderin at all. We leave in 2 months. There is a good Manderin school in our city. Would what we could learn in a 2 hour class for the next 8 weeks greatly improve our trip? Or should we just go in mute and stumble around?

We will have smartphones and a vpn so Google should be able to help us.
Any advice on visiting with no language skills?

Thanks