Hi jackwhittle123
First question: what is the name of this theme? Is it in the WordPress.org repository?
You will actually need to create a child theme for this one, just as Christi recommended. The reason is that you need to edit the header.php file for this theme, and only include the basic elements. Then install Yoast SEO (as Christi recommended), and set your title as you desire it to be.
You should copy the header.php file into your child theme, then change the title tag to this:
<title><?php wp_title(''); ?></title>
After that's done, install Yoast SEO and configure the "Titles and Meta" section. Look for the "Home" sub-section (or similar).
Hope that helps
