“Your school’s math system must be behind… most schools here have 7th and 8th graders in algebra and 9th graders in geometry.”
Not true everywhere. In my state, algebra is normal for 9th grade and accelerated students will take geometry.
Recently, there has been more and more talk of not pushing kids forward on math too rapidly. Many articles about it but here is one: http://www.deseretnews.com/article/865577774/New-research-says-the-push-to-have-students-take-algebra-by-8th-grade-has-hurt-not-help-students.html
Bottom line, take the level of math that is right for you and recommended by your teachers. Boarding schools offer a range of math levels for entering students including Algebra 1.