Hello admin , I'm 17 years old , ivorian but turning to 18 very soon ,

one of my friend I met in Kuwait in school wamm invited me to China , but I don't know what are the process , how can I apply for visa ? Did I need any sponsoring letter from her , I would stay with him at home and I talked with his mom they are fine ......its in Beijing they are stay
Tell me how to apply for visa