Más ejercicios en pablomonteserin.com
<!doctype html>
<html lang="en">

<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <meta name="robots" content="noindex, follow">
  <!-- Bootstrap CSS -->
  <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.1/dist/css/bootstrap.min.css" rel="stylesheet">


  <title>Hello, world!</title>
</head>

<body>

  <div class="row">

    <div class="col order-3">
      Columna 1
    </div>

    <div class="col order-2">
      Columna 2
    </div>

    <div class="col order-1">
      Columna 3
    </div>

  </div>

</body>

</html>