Hi Chrissy!
I can see that there’s an empty widget in the “Third Front Page Widget Area” of your site which is causing the content of the first widget to only be displayed across half of your screen.
To remove the widget, navigate to the Customizer and then Widgets > Third Front Page Widget Area. Click on the widget to expand it’s settings and then “Remove.”
After you’ve removed the widget and saved your changes, you should notice that the content of the first widget expands across the whole width of your site.
I also wanted to note that your site is hosted by WordPress.com.
These forums are for folks running the WordPress software on their own hosting, not on WordPress.com. If you need further help customising your WordPress.com site with CSS, feel free to post in our dedicated forum here:
https://en.forums.wordpress.com/forum/css-customization
You can also access the live chat support option when available here:
https://wordpress.com/help/contact
I’m going to close this thread but feel free to contact us via either of the above routes.
Thanks.