Content Not Resizing

Just trying to figure out why my websites content, images, etc. does not resize to the internet window. Here is a link to what I mean. As you see you have to use the slider bars to see the content to the right. I’d like it all to resize to the window.

https://crystalclearphotos.net/portfolio-pinterest/senior-portraits/

The template I’m using allows it to look the way I want but it looks like maybe something in the CSS code is making it not resize. Here is what I’d like it to look like. As you can see, the content fits in the window and is not pushed to the right. Any ideas?

https://photology.jegtheme.com/portfolio-pinterest/sleek-living-room/