Hi Surya Selvakumar,
If you want to add product to cart follow these steps,
Start by doing some learning paths and get to know how Mendix works. This will give you a good baseline of the platform.
After that write down what you need, for example: customers, products, cards, cardentries, orders, orderlines, prices etc. Convert that into a domainmodel.
We can help you with any questions, but you’ll have to built it yourself.
Start with downloading the Base application. This will give you a kickstart as it does contain several entities that you need: Person, Company, Product, Purchase- and Sales-Order, Invoice. Gets you on your way:
https://marketplace.mendix.com/link/component/117760/Tieka/Base-application