Qualifications
Once upon a time, justices of the peace didn't need a specific degree in order to be elected or appointed. These days, though, it's tough enough to find a state that even has this position anymore, so be prepared to stand out when the magical unicorn of a career presents itself. You'll probably want some legal experience for this.
What does legal experience mean? Law school, my friend. If you want to get the experience, you're going to have to tackle the academic behemoth that is law school. You'll study until your eyes begin to burn, write until your hand goes numb, and spend more hours doubting yourself than you can count. Just know that if you survive, it will be worth every last agonizing moment...until you get that first bill for your student loans.
Do you love telling people what they don't want to hear? Hopefully the answer is yes, because that's what you'll be doing most of the time. No one wants to hear that they're guilty or that they have to pay a fine, but it'll be your job to tell them. Good luck with that.