First of all, remember that all Disney parks are perceived around the world as American Parks - and the visitors in each country expect to hear and see a lot of English language.
While there are a few attractions that you require either a hand-hand translater in which you choose the language, almost everything at the foreign-speaking parks is done in a special sound system that broadcasts several languages as once - your native ear picks up your native language - that system is the same on all the rides like the haunted mansions, Pirates of the Carribean, etc in all of the international parks. The only parks that do not use that sound system are the US parks, which broadcast in English only.
You will have absolutely no problems understanding what is being said or reading any of the signs.
All of the live attractions use something I have dubbed "Disney Speak"...whether in Japanese or Chinese of French, each of the live attractions are done in the native language AND english with two hosts...
They work something like this:
Narrator will say (in French or Japanese) Welcome! How are you doing? Having Fun?
The Second Narrator/host will reply (in English) Hello! I'm doing fine! Are you ready for a great show?"
The Original Narrator will say (in their language with a great big smile and nod of the head) Yes, we are ready for a great time!
The English narrator will say (in English) "Great, then lets get started"
The Original Language narrator will say (in English) OK!
etc
etc
etc combining both languages. Your ear eventually learns to pick out the one you are listening to and pretty much ignore the other. This is consistently used across all of their parks.
All of the menus in the restaurants and snack stands are in both the original language and English. There are photos next to everything, even things like photos of the brownies.
The last thing Disney wants is ANY language problem in their parks. You will never be in a situation in which you won't understand what is being said or done. This was one of the original big complaints at Disneyland Paris resort, for example, that the French locals said there was too much English being spoken -- but today, that is the international language.