I felt this way in my first semester last year. I was trying to summarise the lecture notes and the text and found myself writing pages and pages of useless information. I know the feeling of the lectures sometimes talking about strange content - usually it's because I have become disinterested and my mind wanders.
I have to say though, youtube can be a big lifesaver for your study.....If there is something you are not sure on, search for a video in youtube. So far I have found it really interesting to watch a 10 minute video that a lecturer may spend 1 hour explaining.
I think the other most important thing is make sure you understand the subject/lecture objectives for each works work. Doing the homework or textbook questions will help you heaps.