Hi Katie!
Thanks for your question. First, my congrats on your upcoming first trip to
Disney World! It will surely be a magical and fantasmic time for you. My first trip to the "Happiest Place on Earth" didn't occur until my early 20's, but the experience captivated the child in me. If you ask my wife, she would tell you I'm one of the Neverland Lost Boys, because ever since then I've never really grown up. :-)
One of the many things that Disney does exceptionally well is ensure
all attractions can be enjoyed by those of all ages: the young, the tall, the old, the small, and everyone in-between. Yes, adults are able to ride and experience ALL the attractions at all of the theme parks. You will find some that are more particularly child/preschool themed (2 that come to mind are Dumbo the Flying Elephant and The Magic Carpets of Aladdin at
Magic Kingdom), however, if you look at those standing in line there are many adults waiting to ride, even those with no children (those rides I just referenced are large enough for adults to sit in as well as children).
Perhaps the only rides I can think of that are truly "kids only" are not even in the 4 theme parks. On the Marketplace side of
Disney Springs, they have the Marketplace Carousel and the Marketplace Train Express, both rides are tiny and wouldn't accommodate a grown person. Other than those, that's about it!
May you have a magical time on your first Disney vacation, and may the child in you come bursting forth, as it was for me!
Terry