Well, you should really just pick the subjects that you think will get you the highest grades possible.
However, I definitely think Legal Studies is good for helping familiarize you with legal terminology and the basic concepts of our legal system. So I would definitely recommend that.
I think English will probably help you too as there's a lot of reading and writing in Law and good writing skills are essential.
I think generally they recommend for law a high level of English, so I would do at least Advanced.
As for legal studies, if your school offers it, you might as well do it if you are interested in doing law, but it definitely isn't a necessity. Many people I know doing law never did legal studies (it wasn't even offered at our school).
You should just do the subjects you really like and are good at, to help you get the highest uai possible.