Don't be afraid...
Man,
I wish I saw this post last week. Yes, Carnegie has some of the toughest hill climbing in the state, and some very challenging trails too. That being said, do not let stories on the internet scare you off Carnegie. I learned to ride at this park, and if you are riding with people that know the area, you'll be fine.
I'd love to meet you out there, maybe sometime in November. There are lots of trails at Carnegie that you would enjoy riding, and would also let you see what the park has to offer you when your skills improve. Sometimes it's fun to ride to different places and just watch the people who ride better than you playing in different sections of the park (hills/road jumps/etc).
PM me if you want to hook up and ride sometime. You won't get in over your head, I promise!