I'd hazard that most people either have rose-tinted glasses and live in the clouds prior to or at the beginning of their courses or dislike or even hate it. There is no definitive way of knowing whether you will like law, as every person and every case is different; however, some things that could suggest you might like it have been outlined above and other things that you could do to see whether you might fit in law have been outlined above too. Some things you can't really tell, such as whether you'll like the law school, the future, etc., but don't get too ahead of yourself either.
If you have the opportunity to study law, give it a serious go to see whether you enjoy it and see whether you can last the length of the degree, whether the real/opportunity costs are justifiable and indeed justified.
I should warn you that, as you start out, you'll probably be really naive and view the world through rose-tinted glasses, living in the clouds, or dislike or hate 'law' (Foundies or Intros, both of which are known for their issues). If you do suffer from the blues, there's always help from CaPS, those that came before you (e.g., graduates), and those that are before you (i.e., academics).
You'll really like law (if you do) after Foundies or Intros, when you start studying substantive law courses, or when you start a core or elective that's your thing, your niche.