Teaching in China is good, but you can't expect a perfect life there. The major cities are great, but if you are to live in provinces, you should be prepared to live really simply. Chinese people are friendly, but of course, there are some who are rude as well. This shouldn't be surprising because I don't think there's a place in the world where everyone is kind and friendly.
So you're going to Birmy International English School? That's interesting because I used to teach there, too. Birmy was actually the third language school I went to in China, and by far the best as well. You don't have to worry about your visa because they will take care of that for you. Accommodation isn't a problem either as the school provides the housing for their foreign teachers.
As for Chinese students, well, they are so much different from our students here in the US. Chinese learners tend to take their English classes easy because it is in fact the most relaxing class they have. They enjoy playing games and doing interesting activities, so make sure you always have one for them.
I think Birmy English is an excellent choice, especially because it's your first time to teach abroad. As long as you are positive and friendly with your co-teachers, there will be no reason for you not to enjoy your stay in China.