Nope, lived in So. Cal. until I was 23 and have never been to any number of the western National Parks. I have been to Yosemite (WAY back when Mirror Lake was actually a lake and you didn't need to make a reservation in the first 10 minutes of January or whenever they do it. Just drive in, pick a spot, put up your tent and put money in the box every day) and Yellowstone as a teen.
Sounds like you're going to have a great family trip!