Do your readings, go to class, participate and start your assignments early and you will be fine. If you do these things you wont be cramming or sending in sub-standard work.
Do not expect high marks straight away as law and university involves a different way of thinking, studying, researching and writing.
The best you can do is make the most of all the opportunties you can, listen to your lecturers, especially in your introductory subjects as they will be teaching you how to write essays at university level etc. If you need extra help most uni's have essay writing courses, uni-prep or skills courses and mentoring programs - all of these are helpful and even if they teach you what you already know, you can still make friends.
You will find as each week passes you will read and understand faster, know what you must read and what you can skim and you will also begin to think like a lawyer and more independently.
I averaged credits in my law subjects for the first year with one fluked HD by attending almost every class and doing the readings, my marks improved as I got used to the university style of learning and my skills developed.
It wont be easy but you dont need to make it harder for yourself do you work and dont miss class just because you can.
Good luck
p.s. when you have open book exams try and summarise your notes as much as possible, at the most you only need a few pages and the textbook (tabbed) as a safety net. You will see people take in as much as they can, but in the end it just wastes time. My torts exam in my first year only allowed us ONE a4 page and i survived.