Patents can be applied to China National Intellectual Property Administration by themselves or through patent agencies. After the application is passed, they can be protected. People can ask the Municipal Intellectual Property Office for management, or directly sue them in the Municipal Intermediate Court.
After the patent is granted, it is not only limited to county-level cities, but also valid throughout the country. In view of your lack of patent experience, you can consult your local agency. The cost of a patent plus agency fees should be several thousand yuan.