My sister is a lawyer this is what she had to do .
You have to have a BA degree in something doesn't matter what its in , her's is in mechical engineering.
Then you have to take the LSAT (Law School Admissions Test),depending on what the school requires as a passing score determines if you get accepted.
usually law school is 3- 4 years depending on how agressive you are (and if you need to take pre-law courses). once your ready for the bar exam (the test you have to take to become a lawyer ) that is usually over ALL 4 yrs. , also don't be surprised if the first day of the test you have 300 taking it and the next day you have 200 , the test is ery hard and not everyone passes it on the first try.. no notes no books you can't use anything to help you take the test.
if you dont' pass it your allowed to try again but you have to PASS the bar in order to practice law. Also if say you pass the bar in New York and move to CA you have to take the bar exam for CA .
My sister lives in texas and although can practice law in texas and AZ she had to take the bar for both states.
it doesn't matter what your BA is in but you have to have that before you apply to law school.
Good luck