There are so many things that are just not explained and even when stopping the video and going back to check, there are things that are not explained. I have to assume things, so this is not a course. This is a demonstration video.
My mirror is like 10 years away from where it should be. 
At some point we have to extrude this part of the car but mine just extrudes the lines not the entire face.

then when I fill those up with ctrl + F as mentioned in the video earlier. and I try to move them like in the video, this happens.

so no sorry this is not a beginners course if things are not clear from the get go.