It's Rally-O and the O stands for Obedience. It's a mixture of agility and obedience, more on the obedience when you start. It's bit "friendlier" than Obedience, you can talk to your dog as long as you don't chastise him, only encourage him. For the novice title your dog works on leash, then you go off leash for the rest. I've heard a lot of people say they prefer a, or a couple of, basic obedience classes first and by co-incidence that's what we did. But I've heard obedience people suggest Rally as a way to snap up their dog's heeling. One can benefit the other. Not sure if you can do the same type of things we have in Canada but there is a Working Level in CARO where you do stations with bits from Utility in Obedience and things that resemble field trial work, distance retrieving and moves that look like freestyle or other games.
Go to a class and watch first, always a good idea to see how the trainer works with the other dogs and how you think it will work for you two.