eCommerce sites are dynamic sites which include shopping cart and other modules to manage online stores. There are many open source carts available online which can be used for basic ecommerce website.
However, it depends on the number of products, and the traffic on the website you are expecting in near future. Sometimes it is better to use open source carts and other times it might be viable to custom design the shopping carts for the best functionality and traffic handling of the website. We can work with you to analyze the requirements and scope of the website and help you decide which cart to use.