Here is how to change the default intro text on login to my-account page in WooCommerce.
Hello admin (not admin? Log out)
From your account sidebar you can view your recent orders, manage your shipping and billing addresses and edit your password and account details.
Make a woocommerce/myaccount folder structure in your theme if not already existing and move into it the original woocommerce file woocommerce/templates/my-account/dashboard.php
Then you can edit where appropriate and also remove or add in any custom end points that you have created.