You can check in early to your resort before you head out to the park. Your room may or may not be ready, but you'll have your Kttw cards and they will text you when your room us ready. And you can leave your luggage at resort with Bell Service.
I'm not sure what kind of reservation you have, but from the sound of it you have room only, and bought your tickets separately. If this is the case, you can ask them at check in to put your tickets on your Kttw card.
Another thing is if you are driving down, then you will have to pay for parking, until you do the resort check in, and can provide the gate at the parks your parking pass issued by the resort, or your Kttw card.