U of T is the most prestigious law school in Canada doing your undergraduate degree there might help your chances of getting into their law school but not necessarily.
To become a lawyer you must have a four year undergraduate degree (you can get a degree in anything and apply to law school, it really depends what kind of law you want to study. sociology is undergraduate degree as you can take a lot of criminal soc classes, psychology can also be a good one, so can political science, as well as philosophy. There are law courses you can take in undergraduate studies but few uni's offer enough of them for you to major in law). i am not sure if you need an Honors degree to get into law school ( it is a four year degree just like four year general degree only you have fewer electives)
it might be a good idea to take a few philosphy, sociology, psychology and political science classes at your highschool if they offfer any it will help give you an idea of what you enjoy most and might want to major in in university.
after undergraduate (well in your last years) you take a test called the LSAT's the law schools you apply to then look at your LSAT mark as well as your university grades when they consider your application. law school is very competitive and you must do well in both school and on the LSAT exam.
You then do two more years of school, at a law school.
After that i think you must do a one year apprenticeship and then you can take the "bar exam" (not sure if the Canadian equivalent has a different name), and if you pass that then you officially become a lawyer.
