Lawyers do a considerable amount of research, reading and writing, but this is not the whole story. Communication and negotiation skills, interpersonal relationship management and leadership abilities are also crucial for a career in the Law. Spending some time abroad and/or engaging in extracurricular activities within your community can help you develop such skills.
There are no specific set of activities which increase your chances to get into and succeed in law school. In particular, your activities do not need to be law-related. That said, law schools will favor consistent and deep commitment in a few activities over superficial involvement in many disparate activities. You extracurricular activities should reflect your personality, values and personal intellectual path.