To do this class, or to do any sort of drawing, you don't really need that many pencils.
They come in different hardness, from H to B.
H is the hardest, which means that you run the pen across the page and it hardly leaves a mark. B6 or 8 is the softest, like molted graphite, and gets you really dark shading.
To start, get a middle of the road pencil. HB. It will do pretty much everything we need at the start.
Another thing you want is a good eraser.
Well two erasers actually.
The first one is either the little rectangle one, white or, pink, or whatever, good quality eraser. I personally use the one in a pen, because I have a background in business, and those are good for erasing numbers out of financial statements and budgets. And because they're a pen, they don't disappear quite as easily.
The next type of eraser you want is the kneaded eraser. Those are so fabulous. They allow you to make tiny corrections, work on your shades and gradings, and because you can change the shape, it can get into tiny areas that the other ones can't.