The code

<!DOCTYPE html>

<html>
  <head>
    <link rel="stylesheet" href="styles/style.css">
    <title>
      Practice
    </title>
  </head>
  <body>
    <div class="first-red">
      <div class="first-blue">
        <img src="images/cat1.png">
      </div>
      <div class="second-blue">
        <p class="third-blue">Oliver</p>
        <div class="fourth-blue">
          <img class="second-red"src="images/dog1.png">
          <p class="third-red">
            2 mutual friends
          </p>
        </div>
        <button class="fifth blue">
          Add Friend
        </button>
      </div>
    </div>
  </body>
</html>