There's no cure as of yet for the common cold and it takes around 7 to 10 days for the common cold to go away but sometimes a cold virus can last up to 14 days depending on the strain of the cold virus.
When you have a cold you should drink warm liquids such as warm tea and drink some Orange Juice for the Vitamins.
Eat foods such as chicken noodle soup, Ramen Noodles etc.
Take some over the counter cold medicine to help with the cold symptoms and help with congestion.
Adding humidity to the air using a humidifier or vaporizer in your room can help to clear up a cold virus as well.
Make sure to get plenty of rest and within a week or 10 days the cold should be gone and you should be feeling better.
However if you start having trouble breathing or chest pain seek medical attention because you could be catching or have Pneumonia which can be fatal if not treated.