Connect registration codes are not always included with a text book purchase. Some book stores have the option to order and sell Connect bundles in which the registration codes are included with text book purchases. If you did not receive a registration code with your purchase, you most likely did not purchase the Connect bundle. Please check with your place of purchase for more information.
If you did not purchase the Connect bundle, you may always purchase access to Connect online when registering for your instructor's section. Alternatively, you may also check with your book store as some stores offer the option to purchase registration code cards.