After you put everything you want to purchase in your cart, click proceed to checkout.
Click on the icon that says apply a gift card. Type in the code on your card. The price of your purchase minus the amount on the gift card will be your new total, and you will need to select a second form of payment(visa, mastercard). After you have selected another form of payment to cover the leftover balance of your purchase, click confirm payment.
If you do not have a credit card you should just visit your local Barnes and Noble to make your purchase.How do you buy a book online from barns and nobles with a gift card..?
If you got that gift card that long ago it probably has no more money on it because after 12 months most gift cards will deduct 2.50 per month after the first year so there probably is no more money on it but for online you just type in the number like you would on a credit card. Ask a parent to help you.