How do I find out whether I have applied for a patent (in the United States)

Should we say "published" accurately, because if the American patent is applied first but not published, no one can find it.

If it has been published, if you know any information such as patent number, publication date, applicant, theme, etc., you can go to uspto, the US patent and trademark website.

My English is poor?

I have to find a professional company, but it is usually very expensive. If you search for a topic, it's estimated to be 2K, and if you search for an article accurately, it's estimated to be 200.