Can you get access to past papers? They would help you understand what question type will come up.
Also, if you just learn the lecture notes, you will pass but it won't give you a very good grade. For top marks you need to do wider reading.
It's normal at uni to not have any specifications. Remember, there is no exam board as there were at A levels.
Your lecture notes will tell you the topic, and from there you will have to search for more resources and read around the topic. No one knows what lectures will be relevant and which won't. In the end, the point is that you should be able to answer questions on ALL the material.