Excuse me, I have a product planning thing, but I haven't applied for a patent. Can I sell it to the company? If so, how should we proceed? thank you

Of course, you can contact the enterprise directly, but you don't have any protection at this time. If the other party knows your content and applies for a patent on their own, there is no reason for them to cooperate with you. Because the patent law of China only protects the first applicant, even if the applicant is not the first inventor.