If it is your own invention and you need to apply for patent protection, you can directly log on to China Intellectual Property Network and ipr.com/, and download the special form in the data center. There are three forms: invention patent request, utility model patent request and design patent request. According to your patent type, fill in the form, submit relevant information and mail it directly to the Patent Office of the Intellectual Property Office. Decide whether to accept it, then inform you to pay a certain fee, and then publicize it online for one year. If there is no objection, the type of patent you declare will be granted and the state will protect your patent. The cost is probably within 500 yuan. It's best not to ask intermediaries to handle it for you, because intermediaries charge a lot and the effect is the same.
If you want to buy someone else's authorized patent, you should negotiate with the patent owner.
You can go to your local science and technology bureau (the local science and technology bureau has a patent office and the provincial intellectual property office) for consultation, so you will be more confident.
If there is anything you don't understand, you can leave me a message and continue to communicate!