Thanks for the replies everyone. I usually sit on the hills. I always sit except for the very steep sections where I feel like I don't have a choice (ie I wouldn't be able to turn the pedals if I stayed seated). I guess I'll keep praciticing and see how much progress I make. If I'm not making much progress, I'll get the 30t cassette. After just having bought the bike and all that goes along with it, paying for another RD to accept a 32t is not an option at this point.
I appreciate the info about hill repeats. The hill that I ultimately want to get up is around 1.5k with an average grade of 10% with sections as steep as 18% so that's not realistic now, but there are some easier hills that I can practice on to improve my power/weight ratio and strength endurance. Thanks.