Disney typically tries to be inclusive in the way they build their rides. You'll find that Disneys rides are made so that they (for the most part) accompany people who are plus sized, which is different from a lot of places. Disney goes out of their way to try and include everyone. However, you may want to be conscious of some of the older rides that haven't been redone.
Though you may want to be conscious if you are going to universal studios. They have 'tester' seats just outside the line for the ride so you can see if the ride will suit your size.
Anyways, best of luck and have a great time!