Check that the cold water supply is turned on. This picture shows the tap is 'open' and water should flow. If your tap is round like a sink tap then turn it anti clock wise just like you would to turn a sink tap to make the water flow:
The next image shows the tap is shut and no water will flow to the machine:
If you find that your tap is in this position twist the tap until it is in line with your pipe. Now your machine will fill with water!
It is also worth making sure that the blue tap is not broken. If the valve inside the pipe has seized then turning the blue tap with force may cause it to break, and not actually be opening the valve in the pipe when you are turning it. You may need to call a plumber to repair the tap if it is seized or broken. If you are unsure that water is coming out of the hose a good way to check is by turning the tap off, disconnect the hose and place in a bucket and then turn the water back on. Water should flow into your bucket. If it does not the again a plumber will need to be called out.