I'd say English Language, History and Ethics and Philosophy are some of the top ones to take a look at, sometimes they don't want you do have actually studied law at A-Levels so you're more of a 'clean slate' but you should have a look at universities and what they ask for. Even though it seems early they usually have a few subjects that they like to see you take.
And I know some of the subjects weren't on the list but I hope it helps!