We can style as many elements as we want inside the style tags, as long as we add a space between different rules.

<html>
<head>
<style>
body {
background-color: lightBlue;
color: white;
}

h1 {
font-family: Helvetica;
}
</style>
</head>
<body>
<h1>The Social Book</h1>
<p>Sign up with us</p>
</body>
</html>]]>

Make sure to pick h1 followed by { and then font-family: Helvetica;, }.