didnt study , in china you can get by w/o knowing chinese but it is best nto learn use chinesepod free on torrent

I got by my first three months here with three phrases

你好ni hao hello
谢谢xie xie thank you
冰啤酒bing pi jiu cold beer

Everything else you can pick up on the way.

I took a few Chinese classes in high school and college, so came to China having basic language skills. It has been helpful when traveling in cities where there aren't a lot of foreigners. But if you're here long enough, you'll pick it up and be able to get by.

Most of what you'll learn will be here.

Just learn some travel basics.

I have learned Chinese for 2 years before coming here.

But they never teach you the right things at school.

The most important sentences or words you need to learn, aside "Xiexie", "Ni hao" et "Zaijian" would be :
"Tai gui" (too expensive),
"Duoshao" (how much),
"Bu yao fan wo" or "Bu yao darao wo" (Don't bother me, leave me alone),
"Bu yao" (I don't want,...except if a woman propose you sex :) ),
"Qu si ba" (Go to hell)
.......list is not exhaustive

No, I didn't learn any Chinese before I came here. Sign language helps and certain gestures. Don't forget there are a lot of dialects in China, so what you learnt may not be that helpful.
I would say, don't worry too much about it at all. Go with the flow and think about your own language and how sometimes it is mis-understood at times. If you have a job to come to, then it seems obvious to me that someone can speak your language. I would think in Beijing a lot of people can understand someenglish. Good Luck!!