Okay, first, is the freezer working, but not the fridge? If so, the vent is clogged. Air flows through a vent in between the fridge and freezer. Two things to do would be to defrost the system by turning it off. After it is fully defrosted, clean it, open the vent and clean it, check for anything that could block air flow. Plug it back in and feel for air flow, especially between then fridge and freezer.
Also, listen to hear the compressor kick off. If you do not hear it go off, then you may need a kickstarter. It's like a giant capacitor you attach to the fridge's compressor to get it to turn over. You can order one online or buy one at a fridge parts replacement store.