Set category page title in custom theme [closed]

In your functions.php of your theme file add the following code, taken from Remove “Category:”, “Tag:”, “Author:” from the_archive_title.

add_filter( 'get_the_archive_title', function ($title) {

    if ( is_category() ) {

            //being a category your new title should go here
            $title = single_cat_title( '', false );

        } elseif ( is_tag() ) {

            $title = single_tag_title( '', false );

        } elseif ( is_author() ) {

            $title="<span class="vcard">" . get_the_author() . '</span>' ;

        }

    return $title;

});

Of course you need to read about how the functions.php works. https://codex.wordpress.org/Functions_File_Explained