Requirements for F visa

I have been offered a traineeship for 8 months in zhuhai..I got the invitation letter but I just found out that they another document from the ministry of foreign affairs from MY company showing that they are sending me to china on a business trip and also that my company and china company have been doing business and have a good relationship in order to issue the letter of duly authorized unit.

Since im unemployed im not sure where to get this letter from. This is why I wanted to ask how do you get interns visa app processed? What are the requirements for an it? Is it f or m category?

Looking forward to your reply.

Regards,
Salman Chachar.