90% of admissions is your GPA and your LSAT score. The rest is "soft factors" (i.e., recommendation letters, work experience, etc.). The calculus changes a bit for underrepresented minorities.
The most important thing is keeping your grades up and going to office hours. Make sure you are close with a couple professors so that they can write you recommendation letters.
You should set aside at least a couple months to study for the LSAT. Most people work for a year or two before law school, and take the LSAT the summer before they apply. If you have the energy to study/take it this year, it opens up some interesting options like the
Harvard Junior Deferral program. But most people won't worry about the LSAT until after graduation.
The last thing is to sure that you don't have huge gaps on your resume. You don't need millions of clubs and legal work/internship experience. Just make sure you have something on there.