You may have no credit history or too little credit history.  Use these tips to build one a good one!

Open a checking account. Although checking accounts aren't "credit," checking and savings account history can be included in your credit report. Keep the checking account active and manage the money carefully-don't bounce checks. If you are new to managing a checking account, avoid using a debit card with it because it's impossible to keep track of what you've spent. If you muse use a debit card, save receipts and write each debit in your check register immediately.

Apply for and receive a credit card. To build credit you will need to hold the credit card in your own name, not in a parent's name, although a parent or other adult may need to be co-signer. Where can a teen find a card:

• Credit union Do you have a membership?  If not Join one.

• Store credit card at a department or specialty store where you shop regularly. Be sure they report the status of accounts to credit reporting agencies.

• A secured credit card. Secured credit cards require that you place a certain amount in savings. They typically have smaller credit lines and higher interest rates. A secured loan is guaranteed by the money you have in a savings account. It offers a lower interest rate. After you receive the credit card, make only small purchases, and pay the bill in full when it arrives and well before the due date. Doing this regularly over time helps build your credit history as a prompt payer. Never be late and never skip payments. Don't fall into the seductive traps of credit cards-overspending and/or making minimum payments. By paying off the balance in full each month, you probably won't incur a finance charge "interest charged on an outstanding balance," but it's still important to keep rate in mind when shopping for a credit card.

Small loan for a planned purchase. If you are working or have been saving toward a middle-sized purchase such as jewelry, or a computer system, you may wish to consider a small loan to pay for it. Again shop your rates, the retailer may offer a loan plan but interest rates are typically very high. Explore what your credit union may offer. A loan cosigned by a parent, a loan secured by a savings account, or a Kwik Cash line-of-credit are loans for which you may be eligible. To build good credit, make all loan payments on time; don't be even one day late.

Auto loan.  A number of dealerships offer special programs for first-time buyers. The objective of the dealers and manufacturers is to make young buyers life-time customers. Eligibility requirements (including age) vary. But if you're eligible for a dealer's "first time buyer" program, you're usually eligible for a loan from the credit union or bank. Be sure to compare all financing rates and terms.  Avoid "Buy Here, Pay Here" type car lots if you can and if you do use one, DO NOT EVER BE LATE.  They may repossess your car and keep your down payment.
 

More help:   

Restoring Your Credit     

DIY Credit Repair Checklist