It sounds like you have your base layers and outerwear sorted
Just gonna mention, don't worry about a backpack to wear on the slopes. Leave your extra gear and snacks, water etc in the car or find a locker to put it in. If you are learning you don't want anything swinging around on your back.
Also, don't listen to music while you ride. You probably weren't going to anyway but its worth saying. Its a distraction you don't need... and you won't hear what the instructor has to say
My 2 cents