Every HTML page has the same basic structure:
<!DOCTYPE html>
<html>
<head>
<title>My Webpage</title>
</head>
<body>
Content goes here
</body>
</html><!DOCTYPE html> tells the browser this is an HTML document. It doesn't have a closing tag.
<html> wraps the entire page. Everything else goes inside it.
<head> is for page configuration. The <title> tag inside it sets the text in the browser tab. You won't use <head> much beyond that.
<body> is where everything the user sees goes. This is where you'll spend all your time.