JSFiddle - React, Tailwind, and code Playground
HTML
<p><span> <a class="signUp" href="#">Sign Up!</a> </span></p>
<div class="signUpForm">
<h3 class="title">Join our email list!</h3>
<form action="URL GOES HERE" method="POST">
<label for="email">Email:</label><input type="text" id="email" name="Email"/><br><br>
<input type="Submit" value="Submit" /><br>
</form>
</div>
JavaScript
jQuery( ".signUp" ).click(function() {
$('.signUpForm').toggle();
});