>The customer ask me to track inventory with barcode, I don’t know where to start Can anyone help me

Barcode reading is trivial; most barcode scanners on the market today are wedge-style scanners; they link between the keyboard and PC, and when read, the barcoded information appears as if keyed at the keyboard. No special code needed - input into a textbox works fine. Other types of scanners exist, such as serial or RF devices; these normally come with software for integrating with your application.

In the Windows environment, barcode printing is normally simply a matter of using a barcode font to print the barcode, in the same way any other font is used. I'd recommend using a laser or dedicated thermal barcode printer; most dot matrix printers do not create an adequately c,lean image to produce a reliably-read barcode.