The photographs you provided depict what appear to be M & M candies. My assumption is that you are tasked with determining the combined volume of the candies in cubic centimeters, plus the diameter and radius of an individual candy.
First, use the calipers to measure the diameter of several candies. They should all be about the same…but take an average of 10 or 12.
Then, determine the radius by dividing the diameter by 2.
Finally, to determine the combined volume, partially fill the graduated cylinder with water and record the volume in cubic centimeters. Add the candies and record the new volume. The volume of the candies is the difference.