Each merchant will send an order confirmation email followed by an email with the tracking number. Tracking numbers are not generated until after the order is processed and fulfilled. Orders can take a day or two to finish processing depending upon the retailer so expect an email with the shipment tracking code to arrive approximately 24-48 hours later.
Once the order has shipped and the tracking number has been provided, it's best to direct your questions relating to that order directly to the merchant. When contacting the merchant about your order, use the order number in the confirmation email.