First off welcome, second it may help us to know where you are from as there are no requirements for service animals in the U.S. other than to be trained to perform tasks related to a disability which you have and shows proper behavior, of course dogs will still be dogs at times, but the question is if the behavior is quickly corrected or not. But if we know where you are from, it will help some to explain differences in how service animals are handled in the U.S. versus other countries, as it is different here.
Another interesting point is businesses do not have to allow service animals that are still considered to be in training; however, Disney generally will allow them.
One thing to watch for, especially at Hollywood Studios is squirrels. We were there with our friend and her service dog. We were sitting on a bench and her service dog was under the bench and a squirrel literally ran right in front of his nose. A cast member saw it and commented that the squirrel was clearly and deliberately taunting her service dog. And it really was indeed doing so, probably going "I know you can't do anything about it." He did react slightly, but was corrected and it was also understandable as to why.
One other thing to be conscious of are loud noises. On another trip, the same friend and here service dog were coming out of the bathroom in England at EPCOT and Illuminations started right as they were in the hallway in front of the restroom, which echoed extremely loudly. One of his jobs is keeping her safe from dangers, so he ran her away from the noise as fast as possible. So, something to be aware of and it could have looked like he was misbehaving when it was more he heard danger and was doing his job and nothing was going to deter him until he felt she was safe.
As for how things work, any rides where a service animal cannot safely ride will have a crate available.
Also, remember that if there is an escalator or moving walkway, it should be bypassed or stopped as the pads of the dogs feet can get caught and injured severely.
Depending on time of year, you may wish to invest in socks to prevent feet from burning and a cooling vest and add a service dog patch to it, as it can get extremely hot in Florida.
It should also be noted that last I have heard, Disney, along with most theme parks is now strictly limiting to on service dog per person with disability due to some.people having brought what could only be described as packs of service animals in the past and causing a lot of problems. And I believe they are limiting to one service dog per room as well, but I am not as sure about that one.
Disney security has also been known lately to invite those with service dogs that are misbehaving to leave the premises if the misbehavior isn't being corrected or has caused injury to another person. This is a point that has been cracked down on lately from what I understand.