A lot of time on CC we wind up telling posters to cool their jets for awhile, and not to get ahead of themselves.
Not now, not this time. Every school district, every high school has its own culture and its own quirks. Everyone there is so familiar with them that they are not even aware that whatever they do is not necessarily the natural order of things that every human being instinctively understands. Notwithstanding the mobility of the U.S. population, as far as I can tell very few districts or schools that do not serve huge military populations are really good at integrating students who arrive from anyplace else, much less a foreign educational system. It will take a lot of time and a lot of annoying people by asking what they consider dumb questions to get to the point where you really understand how things work. It’s not too early to start that process yesterday.
I don’t know what to do if you don’t know where you will live yet. Try to figure that out. Then do everything you can to learn the local high school system – and not by googling Great Schools, or anything crude like that. You have to talk to people at the schools, and to parents in the community. You have to stalk their websites if you can. Figure out when the critical dates are; that may help inform your decision about when to start. (My instinct, like that of others, is mid-8th grade, recognizing that you are probably setting your kid up for a few miserable months by doing that. The investment will probably pay off in a year or less.)
But it’s not just when to start. Do you need to get independent testing done to qualify your kid for a “Gifted and Talented” program, if they exist? (Watch out for this one. There’s a chance that, coming from a local public middle school, your child could never qualify at the high school level if he or she was not in the program in middle school, whereas coming directly into the high school they would accept independent testing.) When are the sports tryouts, the orchestra, the choral groups, the plays, etc.? How does the ranking system affect what courses kids take? If there are more than one high school, how do people choose?