You have to apply to California Board of Nursing for licensure. Once they accept your credentials they will send you an ATT letter (Authorization to Test) which is needed to take to the testing center with you. Be aware that California will take about 6 months to get that letter to you.
Depending on what type of visa that you are on, that will tell what else that you need to do...............you may be required to complete the series of English exams if you are going to be applying for a green card, as well as the Visa Screen.
As far as your curriculum being accepted, it will depend on whether or not you completed course work in mental health. There are some programs in China that do not offer this and you will be required to make it up.
I would pick up some NCLEX review books and see how comfortable that you feel with the information. That is the best way to start.
Hope that this helps.......................