While on the product page you must click the personalised details tab and enter the details you require on the card or Invitation.
For example, Front: Thomas Age 2. Inside: Happy Birthday Thomas. Lots of Love Auntie Mary xxx
Once that is done you can then click the BUY button to add that item to your basket. Your personalised details are stored with your order. When you have purchased all the items you require you then click the Checkout button in your basket and follow the checkout process. You will receive a confirmation email of your order which will include the personalised details entered for each item.