I have no sage words of advice except to relax. You've done the practice exams, you've written out essays. You're dialed in on how much time to spend on each multiple choice question and each essay.
Day 1 will go by quicker then you imagine and you'll be tempted to rehash it all out in the parking lot with your former classmates.
Just leave and go relax.
The night, I walked down the street from my hotel to find a nice looking bar and ordered a burger and a pint. Freaking out over flashcards in my hotel room before a day of essays was not going to increase my chances of passing. Keeping calm and acting like a human being seemed the best approach.
So relax and get throught it. You'll be fine.