I know programmers in my town who have used that for learners in the same age range you are considering.
My son had a distance learning course (which, alas, seems no longer to be offered) based on the book Approaching Precalculus Mathematics Discretely
that was a good example of using functional programming (in Logo) to investigate mathematics. The book appears to not be in print anymore, but still available from some booksellers, and is a good glimpse at what some high schoolers can learn if they have enough mathematical background.
The local programmers I know who teach classes for that age group are now mostly doing Python courses, as there seem to be quite a few good introductory texts on Python, or else teaching Ruby.
You are fourteen years old. You probably haven't had much good math instruction yet. One of my favorite authors on school mathematics wrote, "The proper thing for a parent to say is, 'I did badly at mathematics, but I had a very bad teacher. I wish I had had a good one.'" W. W. Sawyer, Vision in Elementary Mathematics (1964), page 5. You can find a good teacher by finding good books about mathematics, even if you have never had a good teacher. Many working programmers haven't either, which is why some of them don't see the need for much math background to become a good programmer.
You are young enough to learn a lot of math and to learn a lot of programming. Learning both hand-in-hand will make you a better programmer. One good book that combines both subjects is Approaching Precalculus Mathematics Discretely by Philip G. Lewis
which alas appears to be out of print, but may be available as a used book or from a library. It teaches key concepts of school mathematics while also teaching functional programming with the Logo dialect of Lisp.
A great place to hang out online to learn math and programming is the Art of Problem Solving Forum, especially its subforum on computer science,
which is moderated by a brilliant young man I know who is not a lot older than you are.
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