There are many Youku websites. Look at this. I suggest you take a look at Huang Chunliang's demonstration. Very authentic, every step has a scientific explanation. Very scientific. After reading it, you will have a basic understanding of Wing Chun.

But don't expect to learn in this way. If you really want to learn, you'd better find a master to teach yourself. As Donnie Yen said, Wing Chun is actually a noble martial art. In the past, it was very expensive because it had to be taught and practiced one by one. Many of Ip Man's apprentices are children of rich people, including Bruce Lee.