Thanks for your kind words. About your questions:
a. Does 0L mean you will be starting as 1L this fall? Yup.
b. Do they often wonder "how do you know this is what you want to do?"
The law school admissions process is very much a black box to me. That said, I very much doubt that AdComms (admission committees) expect applicants to know exactly what they want to do. Rather, your emphasis should likely be on hardship and why you want to practice/pursue law.
c. also, I want to know if public health is relatively a new field in law.
No idea, but I'd imagine that a little bit of research would yield an answer.
d. can I ask you what made you want to do JD/MPH?
It all started when I read Tracy Kidder's Mountains Beyond Mountains. Then after a bit of Farmer, Sachs, and some other public health-related reading, I became pretty sure that this is where I want to be. I also know that I love law. So I picked them both.
e. do you think its better to do a joint program or do them separately?
It seems terribly inefficient to pursue them both separately, especially considering most schools now offer joint programs.
**
Take as much time as you need on the LSAT; it'll determine not only where you go to law school, but where you receive your MPH as well (many MPH programs accept LSATs instead of GREs for joint applicants).
Best of luck.