It sounds like you don't have much programming experience? If that's the case then to make a real-life application like this from scratch is far too difficult a project for a beginner. Why not look at one of the free inveytpory applications that you can simply download and start using? Even if they turn out to be not-quite-right at least you will learn a lot about what you really need.
Have a look at things like http://www.top5freeware.com/inventory-management-software-for-windows