I am a high school student, and a native speaker of English. I am also conversant in Mandarin and understand some Cantonese. I am interested in teaching English in China, Japan, Korea, Taiwan, or Vietnam (particularly China or Taiwan) in the near future, if not necessarily after graduation.

My questions are primarily about qualifications. Is it necessary to have a university degree first? I have looked at some of the job postings and many of them do not specifically mention this. Would my age be a barrier (it would be at least eighteen)? What are some suggestions? Finally, what should be done about water, especially if the job was in one of the less large cities...that is, is the tap water likely to be safe? Thanks.