Hopefully, I'll surprise more than I disappoint.
You'll be fine.
I've been to the other ones; redwoods, Grand Canyon, now I know I'm missing out. And we're looking to go either south or west in a few months so the thing's probably gonna continue eluding me.
I recommend visiting in the fall, if you can, early to mid-October. You'll miss the busy summer season, and get to see the wonderful fall colors.