I would suggest a set of 12 Staedtler pencils. They range from 8B to 2H and are perfect for life drawing.
I word of advice. When your class starts make yourself comfortable and then totally relax. Empty your mind of everything then simply look at your figure. Do not tense up your hand or arm, just let things happen naturally.
Remember that there are no two artists in the world that do things or see things exactly the same. Each artist is unique with different styles and different levels of skill. Art is the one discipline where there are no competitors and the only person you have to satisfy is yourself. Do your best and that is all anyone can ask of themself.
You will do great if you allow yourself to. Good luck!
"Creativity emerges only when the imagination is given the freedom it deserves."