The Curt Class II hitch, part # C12027 doesn't include the ball mount, hitch pin and trailer ball. Those are sold separately. In order to tow with your hitch, you'll also need a trailer wiring harness.
For a wiring harness, I'd recommend # C56175. For a ball mount, use # C45520 along with # PC2 for a hitch pin and # 19256 for a 1-7/8 or # 19258 for a 2 inch trailer ball.
I've linked to a video showing a typical installation of the wiring harness I recommended. view full answer...