Editing theme files

Hello. Im having problems editing some theme files. I need to add a class to the h1 tittle in the header (if im right its the header.php file) but cant find the line of code i need. Is editing the header.php file right or am i missing something?

Thank you.

Hello there,

I hope you are doing well today.

Are you referring to the jumbotron that has 2 buttons?
In order to edit the header/jumbotron in the theme you need to edit the “front-page-bottom-header.php” file.

Best Regards,