Hello Andrew,
We don’t have customization options in the free theme however you can make changes here;
1. Whichever page you select to display in the home page banner make sure the page title is what you want to display as a banner title.
2. You can edit the paragraph below the banner inside the particular’s page Excerpt.
3. If you want to set a background image like our demo place the desired featured image in your home page.
4. Regarding button, the text and url is default however if you are familiar with the theme files you can edit it from theme’s header.php file. The button’s design and color can be changed through css if you wish to make changes.
Thanks!