Hi Lorena!
You can get more information and trips with traveling with very young guests on this
website.
Once
you are on that page, you can click on the PDF to the right titled
"Attraction Height Requirements". If you don't see an attraction
listed in the file then anybody can ride. As you can
see, there are not that many that young guests can't ride; Walt Disney
World
attractions are mostly designed to be enjoyed by the entire family. I
know that may sound strange if your only experience is regional
amusement parks, but it's the truth!
By the way, my wife and I have taken our children to Walt Disney World at
least once a year and we started taking them when they were babies;
both visited before turning 1. My wife and I wanted to visit and we
didn't want to wait for the children to grow up; we also wanted to
capture the memories of our babies visiting the theme parks with us and
interacting with Disney characters. Disney makes it very easy to travel
with very young children. There are baby care centers in each of the
parks. There are also changing places in all of the restrooms. My wife
and I carried our babies on a lot of the attractions and stayed
together. For the few attractions where that was impossible, we
utilized "child swap" to allow each of us to experience the attraction
with minimum wait.
A few pointers: go during a less busy time of
the year, such as when older children are in school; slow down and enjoy
the experience of visiting with young children; take your own stroller because your children
will be familiar with it; consider staying at a monorail resort or
renting a car to allow you to return to your hotel quickly to take a
nap, rest, etc; consider a character meal, but don't rush character
interactions until you see how your children respond.