Having danced English Clog & taken workshops in Appalachian style, I would say that there is of course a difference between them, but probably not such a vast gulf that you could learn Appalachian, & then not be able to do English step at a later date when you find a teacher.

Even in English step there are so many different styles that you have to learn each style individually anyway, for example Lancashire dances are very different to Westmoreland dances etc.

You might want to go here chrisbrady
to see whether there is something that can help you.

Good luck