What centerpin did you buy?
Biggest thing to remember is to let go and let it start to drop/spin a little before casting. I just switched to a centerpin at the end of salmon season. I bought a used avon and started out with that. Picked a peice of water that i had all to myself and just practiced. Not really looking to catch anything but just practice casting before i was next to a bunch of people. To tell you the truth, i was told to and expected a large learning curve but didn't find that the case. Within half an hour i had the hang of it no problem. After the first "real" day fishing, you would think i had been using it for a long time. Now, a couple months later, i have an islander centerpin and it just seems so natural like i have had it for years. Just got my first fish on the pin, a nice 10lb wild steelhead. What a feeling. I couldn't image using a levelwind anymore on the river.
Remember to practice first and have fun. Once you get the hang of it, you'll love it.