Hello. I am a Pakistani National but currently living in UK and I finished my Masters course. I want to go to China for my PhD. But I want to visit the universities in China by myself before getting admission there as I want to meet my potential supervisors. Can you kindly tell me what type of a Visa I need?

Secondly my friend lives in China. I will be living with her in China, She is my friend and not my relative so how can she help me in the regard of sending an invitation letter etc?