Content Width Smaller With Same Theme (Genesis/Prose) And Same Settings

Hi

I am using the Genesis theme with Prose as the child theme. I have two different WordPress sites with the same theme and (as far as I can tell) the same settings.

However, my first site has a wider content area.
I would like both sides to be as wide as this one: https://greekbod.com

As you can see this site has a narrower content area: https://redpillreviews.com/blog

I don’t have much of an understanding of CSS and HTML so I’m a bit lost if I need to go into the code.

I have no idea what the problem might be. My WordPress dashboard also has smaller writing on the new site for some reason.

Any suggestions?

Thanks for your help!