Brand New Newbie!

I'm a visiting nurse in the community, which means a working knowledge of many languages (fluency preferred but not yet achieved!) is beneficial. Chinese is my current need with patients. Cantonese is mostly spoken in the community, however, from what I have gleaned Mandarin is a language that many who speak Cantonese are starting to learn in order to converse with mainland China. Since I have a Cantonese speaking patient who is learning Mandarin, I have decided to learn Mandarin at the same time so we can both practice! Knowledge of Chinese idioms would be invaluable. May I join the group to learn idioms, please?