You are never too young to start keeping a record of your personal finances.
When you write down your income and expenses you begin to understand where your money goes.
You may find that you are spending a large amount of money on unimportant things such fast food and magazines.
When you identify your personal spending pattern, you may find that you are willing to spend less on small items, so that you can put that money toward a more expensive item you might be saving for, like a car or a mobile phone.