New customers can sign up for your online store through the main page by clicking on the Create an Account button and fill in the details.
You can add new customers or manage the existing ones through the Customers > All customers section in the Magento admin area.
In order to change the customer details, click on the Edit button next to the customer.
There you can alter all customer details, including the username and the password, the address, monitor the orders, the shopping cart, the wish list items, the reviews and manage the newsletter.
You can monitor the online users from the Customers menu > Now Online.