Firstly you need a domain name. You can register one at about $ 8.99 (RM 29) per year.
Secondly, you need a web host to host your website. The pricing for a quality host normally starts at about $ 4.99 (RM 16) per month.
Thirdly, you will need an ecommerce script/shopping cart (software) to list your product. The ones I recommend are
Magento Commerce (the best free shopping cart) and OsCommerce (the most widely use free shopping cart).