How to Vertically align using bootstrap

1 
<!DOCTYPE html>
<html>
<head>
	<title>Startup Landing Page</title>
	<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
	<link rel="stylesheet" type="text/css" href="style.css">
</head>

<body>
	<div class="container ">
		<div class="row d-flex text-center align-self-center">
			<div class="col-12 ">
				<h1>The Biggest Startup Event Of The Year</h1>
			</div>
			<div class="col-12 ">
				<button type="button" class="btn btn-danger">Find Out More</button>
			</div>
		</div>
	</div>

<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>
</body>
</html>
2

I’ve updated your post. Make sure to format your code when you are posing codes.

Here are classes to help you vertically align in bootstrap.