You wrap the end that looks like a wrist strap on your wrist and then clip the alligator clip to the chassis of your computer. It keeps you from building up static between you and the computer. It keeps the static from discharging through your components when you're working inside the computer.

It isn't supposed to interfere with drawing and if it does there is one of the quick controls that you can program to toggle touch on and off with the push of a button. I usually keep my touch off until I really need it for something then a tap of a button and full control is achieved.

The small, Medium and large are all the same in regard to sensitivity. The only difference is the size. Taking that into consideration the size does matter depending on what you're using it for. I use it to touch up photos and make selection in Photoshop. If you're using it as a drawing tablet then you might want to use the bigger models to get the long sweeping strokes used in drawing or illustration. I would suggest trying the sizes if possible, which can be difficult since they don't have them on display usually. It is the best way to be sure of how it feel with your style of use. Good Luck!!

Elements is not Creative Cloud (CC) this would not be what the instructor is talking about. There are many tools that are the same but CC is much more powerful and if you're instructor is doing anything other than Photoshop in the class this will not have it, such as Illustrator or Lightroom, etc. Adobe CC (the full suite) is many programs that Adobe has and Photoshop is just one of them. You can get an Adobe CC subscription for just Photoshop and Lightroom for 9.99 a month. The full CC is quite a bit more a month. Go to the Adobe web site and you can see everything they have to offer. Good Luck and have fun!!