Great question. I'm a 29-year-old law student, and I still don't know all the different types of law there are. I can tell you right now that most of my classmates don't know all the types of law out there and what type of law they want to practice, either. The next real step for you to think about at this stage may be -- do I want to invest 3 years of my life (and tuition) in law school? To answer that, it will be most important to know certain things about yourself first -- because THAT is what will help you narrow down the area of law you want to work in as you go through law school.
Here's what I knew about myself: I love reading and writing (research) and debate. I am passionate about social and political issues. One of the biggest motivators that propels me to action is social justice. I love the idea of being able to use law as a tool to create meaningful change, potentially in the policy arena (but who knows...did you read the part about my being 29 and still not having all the answers?)
Because I knew these things about myself, I interned with a criminal defense attorney when I was in high school. I found that I loved it, so I kept in touch with him and asked him lots of questions. I talked to friends and family members (and sometimes even strangers) who are lawyers about why they went to law school, what they got out of it, and whether they enjoyed their jobs. I read lots of newspaper articles on law-related issues (to ask myself, do I find the legal "lens" an interesting way to understand the world around me? YES!!) Asking myself these types of questions, trying to get as much exposure to lawyers and legal issues as I could -- these are what helped me figure out whether law school might be good for me, and this type of proactive searching -- coupled with some good, old-fashioned work experience as a journalist -- is what made me realize that I might be interested in pursuing media law after law school (but who knows? My studies and internship experience next semester may help change my mind!)
Lucky for you (and me), the first year of law school gives you a taste of MANY different types of law, and it's all mandatory so you don't have to make any big decisions now: civil procedure (contracts law (how courts hold people to their promises), criminal law (Law and Order, anyone?), constitutional law (what Supreme Court justices think about all day long), etc. Keep an open mind. After my first semester of law school, I found myself LOVING contracts law (WHAT?? Didn't she just say she loved social justice?) and not being as excited by Civil Procedure (that's the class that involves all those social justice issues I supposedly love, like due process/the right to be heard in court.) Your law professors will not only give you an idea of what the issues are in a certain area of law, they are often practitioners who are happy to share with you exactly what it is like to work with these issues everyday in an office.
Law school is really where you will decide what type of lawyer you want to be. Every week, most law schools offer panels and talks during which practitioners come and talk to you about what their day-to-day is like. Law schools usually have a career services office where counselors will help talk you through the different areas of law that might be a great fit for you. These counselors will also news of great internship opportunities during the school year and summers -- getting experience is key to figuring out if an area of law is right for you. If law school is the right decision for you, it is very likely that something in a class or internship/work opportunity will captivate your imagination and strike you as a good use of your skills, as long as you are proactive and keep an open mind.