You will have no trouble traveling in Germany without language. You can bring small amount of cash in $ with you and easily find currency exchange place in big cities. ATM is the best way to get Euro and always gives you good exchange rate though with a very small fee charged by your bank (check your bank before you go) For the rest of expenses you just use your credit cards. The credit cards (visa and MasterCard) are accepted widely in big cities but not small restaurants in Austria.
Try this website: www.hrs.de It has Chinese service and I found out most time it has good rate in Europe. Its services and cancellation policy is great. No fee is charged for booking through it.
BTW, Neuschwanstein in south of Munich is a must-see.
You will fall in love with Europe!