wordpress custom theme
//créer wp-content/themes/myThemeName/style.css
/*
Theme Name: Capitaine
Theme URI: https://capitainewp.io
Author: Maxime BERNARD-JACQUET
Author URI: https://dysign.fr
Description: Mon premier thème !
Requires at least: WordPress 5.0
Version: 1.0
*/
//créer wp-content/themes/myThemeName/index.php
<?php
$echo = "content"
?>
<!DOCTYPE html>
<html>
<head></head>
<body>
<h1>Coucou ! <?php echo$echo ?></h1>
</body>
</html>
//That's all, go to theme in /wp-admin web interface,
//and select "Capitaine" theme in 'Appearence' dashboard menu to activate your brand new wordpress theme