Just echoing what other people have said really, there's no reason for your teachers to care, or for you to worry about what they might think. For all you know they might not actually have a problem with you being trans, you could just be looking for people to have a problem with it because you don't expect things to go completely smoothly. That probably didn't come out right, but I sort of have a paranoia that people will have a problem with me when they really don't.
It's a different environment here at work as we're all adults and a lot closer to our instructors than you normally are at school, but even here the instructors don't really care about what people do. They think that some people are odd, but not in an overly nasty way, and they're all completely professional at work. The only ones that they really think are strange are the ones that are nasty people anyway, they don't care about anyone's partners or anything. When I was at school I never knew what any of the teachers thought, but the few that I did know a couple of their views on things never really cared about anything that went on between their pupils.