That's how to find your order info, track your packages, manage a subscription, and view course pages that you have purchased.
Later you can access your account using the profile icon on desktop/laptop, or the "sign in" menu link on mobile device or tablet.
If you have a subscription but can't log in, you probably didn't create an account at checkout. Register here using the same email you used in your order. Then you'll be able to manage your subscription.