Simple size change for Products on Product Page ...Help! by broke&living

Hi I'm a super novice coder and have been trying to figure out how to change the size of my images on the product page to fill up most of the white space. Since my collection only has three products I figured it would make more sense to take up the space instead of leaving a bunch of white space at the bottom. I'd like the product to land on the page like the image below. Is there anyone that can help with this???