Ask your favorite teacher or the teacher you do the best in their class.
Part of their job is to write recommendations. They will know you by your work. If you have other info to share with them you can always email them.
"Mrs. Brown,
I am was wondering if you would be able to write me a recommendation for colllege. I have enjoyed your class and particularly like the segment on Fibonnacci sequence as found in nature. I am not sure you know, but I am also in the Physics club where I find it fascinating to apply math to other subjects.
Thank you,
Awalese