Cost: application fee 900+ substantive examination fee 2500+ publishing and printing fee 50. If you can get authorization, you need to pay an authorization fee of 205, and the annual fee for the first year is 900. Ps: Students can apply for fee waiver, which can be reduced by 85%.
If you are in Nanning, you can apply to China National Intellectual Property Administration's agency in Nanning, or you can mail the application documents directly to China National Intellectual Property Administration.
Besides, an invention patent can't be authorized just by your application, and the possibility of being authorized is less than half, which has nothing to do with the time of your application. You should consider this clearly. In addition, since you don't understand patent affairs, I suggest you find a patent office to help you apply for affairs on your behalf.