The school is likely to supply you with sharpened pencils, but it pays to make sure that you have enough #2 sharpened pencils before the exam. Make sure that your pencils have good erasers. For some reason, pencil erasers smear when students try to erase their completed bubbles.
Speaking of erasers, the rubbery thick art erasers seem to work best. My school bought a several dozen erasers for students to use during testing. You’ll be surprised at the number of students who ask for erasers while testing. Because marks have to be completely erased so as not to confuse the scoring machine, it pays to give students proper erasers.