Ok I managed to figure it out. Posting below what I ended up doing.
Side note: It would be great to be able to update the copy outside of the functions.php file. Suggestion on how to accomplish that would be awesome.
funtcions.php
add_action( 'my_own_action', 'my_own_action_function',10 );
function my_own_action_function(){
echo "<h3>hello world</h3>";
}
page-title.php
do_action( 'primer_before_page_title' );
primer_the_page_title();
do_action('my_own_action');
The what the file plugin was very helpful in figuring out what file to look for.