Do what fulfills you: Pay attention to what moves you intrinsically, and do more of that, and give yourself plenty of time to do it. Over time, the interest, dedication, or passion will be clear, and it'll be easier for you to speak about those experiences when it comes time to apply to schools. Obviously, do what you need to pay for your living expenses too.
Do what is practical: There's plenty of career advice for what to do to set yourself up for law school (internships, paralegal, jobs related to your area of interest, etc), so I won't cover that here.
Tell the story well: Most any life experience can be framed as unique, relevant, and interesting to a law school admissions committee! AdComs want to assemble classes with people from various backgrounds. So a big part of this will be how you tell your story in a short-form written format. Think about short essays you read online or in magazines or elsewhere. Why did they resonate with you? How do you tell your story in a way that will also resonate with the reader?
Ideally, you'd like to both (A) maximize both prestige/rank and (B) minimize the total cost of attending (tuition, room/board, living expenses, post-grad debt both interest and principal).
Law school admissions is mostly a function of 3 things: (1) University GPA, (2) LSAT score, and (3) Your personal brand or story (see experiences above). Based on (1) and (2), you'll know the range of prestige schools that will likely accept you. If you are on the higher end of that band for a particular school, you'll most likely receive more $ grants from them to incentivize you to accept. Number (3), your personal brand and story, will be the X-factor that distinguishes you from folks who have a similar grade and GPA as you. Be thoughtful about your job prospects and expected income post-graduation vs life expenses (of which the biggest components will be, in rough order: rent, debt repayment, savings rate, necessary expenses, and discretionary expenses). Do the math on this, and revisit the calculation from time to time if things change!
Timing: Don't rush into law school --> work for a few years and build up some savings. That'll make the financial burden of law school easier to bear.
As to prestige vs. financial impact, my advice would be to put more weight on getting an affordable law school eduction, with one caveat. If your goal and dream in life is to be a United States Supreme Court justice or law clerk to a justice, your chances of achieving that goal go up dramatically if you graduate from Harvard Law School or Yale Law School. But for the vast majority of lawyers in the United States (about 99.999%), you can have a rewarding and successful career as a lawyer by going to an affordable, accredited law school near where you live. As someone else said, if you can have both (prestige and affordability (through grants and scholarships)), that would be the best of both worlds.