<?php
if ( is_user_logged_in() ) {
    $current_user = wp_get_current_user();
    $customer_name = $current_user->display_name;
    echo 'Welcome, ' . esc_html( $customer_name ) . '!';
} else {
    echo 'Welcome, Guest!';
}
?>

display_name;
echo ‘Welcome, ‘ . esc_html( $customer_name ) . ‘!’;
} else {
echo ‘Welcome, Guest!’;
}
?>