I had multiple standard length #2 pencils with an eraser and everything. I had 3 or so ~standard sized sheets of scrap paper to use (front and back). These papers might have been a little bit smaller than normal, but they give you more paper than you need. They were tinted blue and attached together at one side to make a booklet.
It's extremely unlikely that you will have any issues with the paper, pencil, or environment. They give you industrial strength, sound canceling earphones. My room was quiet enough that I never bothered with them though.
The MCAT itself is enough to worry about in itself. My advice is to put these details away in the back of your mind and concentrate on your studies. Just make sure you know where your testing center is ahead of time, get enough sleep, eat breakfast, and don't forget your ID.
Edit: You have 10 minute breaks between sections. If you feel like you used too much paper on PS, just let the proctor know as you are heading back in. There were more like 5-6 questions per passage for the VR section.