The biggest mall in Kandy is the KCC (Kandy City Centre), not really the city centre but a mall so named where you can shop for branded goods. The place is home to the islands popular department stores like Softlogic (agent for Samsung in Sri Lanka), Odel (branded fashion ware), Future World (agent for Apple in Sri Lanka) and WAD de Silva (branded watches etc.). There is also a Baskin Robbins and Burger King, amongst others, for grabbing a quick bite.
About 1.5kms from the Kandy train station is the Arpico Supermarket, situated on the Peradeniya Road. There you can purchase your groceries and other household items. You can get there via bus from the city centre or by hailing a tuk-tuk or trishaw as they are sometimes called. The fare is quite minimal for short-distance drives.
Also, on the Peradeniya Road is the famous 'kotuwe kade' kade meaning shop in Sinhala. This budget shop is ideal for picking up cheap household items as well as, inexpensive electronics.