I do not know PHP & I have to develop a Shopping Portal with following Definition :

Scenario: Online Shopping Portal

XYZ.com wants to create an online shopping portal for managing its registered customers and their shopping.

The customers need to register themselves first before they do shopping using the shopping portal. However, everyone, whether registered or not, can view the various products along with the prices listed in the portal.

The registered customers, after logging in, are allowed to place order for one or more products from the products listed in the portal. Once the order is placed, the customer gets a reference order number and the order status should be “order in process”.

The customers can track their order using the given reference number.

The management of XYZ.com should be able to modify the order status of a particular reference order number to “shipped” once the products are shipped to the shipping address entered by the customer at the time of placing the order.

The Functionalities required are :

Create the interface for the XYZ.com shopping portal using HTML/XHTML and CSS. Implement the client side validations using JavaScript. Create the tables using MySQL. Implement the functionality using the server side scripting language, PHP. Integrate all the above tasks and make the XYZ.com shopping portal functional.

How do I develop this application with following proper steps of development ?