Advice on moving to China with my son?

Hello Everyone, I am planning to working in China as a English Teacher. I have got all the necessary qualifications and I have been offered a job in a private language school. The pay is 16000rmb after tax, that's including accommodation allowance per month. The school is situated in Beijing. The salary is substantially higher than what I currently make as a teacher in the UK and right now I can't afford the type of housing that I want for my son and I, as London prices are extortionate, I have tried moving out of London, but the job market outside the capital is hard to find work as a Music Teacher. Mu son and I still live at home with my mother and her partner which is not ideal and frustrated me too the core. I am looking to move to Beijing with my son who is two and a half years old. Now I have been looking into International schools such as The International School of Beijing and Western Academy of Beijing,, they look great and cover a western curriculum, however it is way too expensive I know my salary would not be able to cover that. So my options Homeschool which I could do. Public school or nanny. So I want to know what are the public schools like? How much are they? Do they teach English? Would my son receive a good standard of education there? The education system where I live in South East London is appalling and Luckily enough my son is very young and really can't speak properly yet so the move wouldn't be too difficult or traumatic besides from missing family. Also if he is too young for preschool in China, how much are nannies in Beijing and where would I find a good one? Also in my moving package there is 6000rmb. Medical insurance Bonus of 8000 after first year. I really want to use this opportunity as a stepping stone to teach in a University or a international school in Beijing or perhaps else where once I get this experience under my belt. However, I don't want the experience to be at the expense of my son's happiness. Some advice is needed.