Hello Stephanie,
Thank you so much for your question. We designed the theme in a such way that, it is now compatible with all types of devices.And if you change the margin, padding for the desktop view, you have to check on all the responsive devices too. So, please use the CSS property to make the design as your need and don’t forget to check the changes on the small devices. We can only mentor you on this issue because there is not any quick method to change the layout. If you are familiar with Codes, you can customize the theme as your need. Other wise, hire a customizer.
Note: Child Theme is recommended to customize theme. https://codex.wordpress.org/Child_Themes
Best Regards,
Acme Supports