Soon enough there will be the usual motley crew coming on here bleating on about how you need to know the subjects etc etc. In the case of Air Law and the majority of Ops my money is on rote learning from the BGS website. Very little of those subjects you will use during your career. If your instructors are any good then hopefully they will highlight the bits that are relevant and the rest will be a matter of ticking the boxes. Sad to say it but those are the joys of the ATPL's.