And not as a camp counselor, or waiting tables, or on your novel (or your tan). You need to get a job in a law office, either as a “summer associate” in a law firm, or as an intern in a governmental agency, or as a legal staffer in an advocacy organization.
You need to work for two reasons. First, you have to get some experience. Not only do you need to start developing your skill set as an attorney, but you also need to decide if (for example) private practice is the work environment you want to ultimately pursue.
The second reason you need to work is that in many cases, these summer jobs are your entry into full-time post-graduation employment. Not everyone ends up working permanently in one of the offices they summered at … but a lot of people do. So your summer jobs are both learning experiences and foot-in-the-door experiences. In each case, they are overwhelmingly important.