When I was your age, the only one that knew was my then girlfriend. No way would I have ever told another living soul. Keep in mind, there was no Internet and readily available information about gender issues or just crossdressing.
I have been married 3 times. The only wife that never knew was my first. ( married way to young and divorced in 5 years.) Since then, I've told my SO's and a close trusted friends; mostly female. So far the only bad reaction I have faced was my older brother. He is one of those so called born again Christians that goes over board with his religion and has become very intolerant. Up until recently, we have not communicated with each other for close to 5 years. We have mended the fences and he knows better then to push his beliefs on my face. He is almost human again.
I would suggest you know, or have a good idea, of how anyone you feel you have to tell will react and how they feel about any alternate lifestyles. The only mistake in judgement about who I've told, was the one brother. Well over a dozen friends accepted it and if anything, our bond has become closer and better.