My high school wasn’t well off enough — nor no where near big enough — to have a whole class devoted to photography. I took one once, in college. It wasn’t very helpful to tell you the truth; I did learn how to make a pinhole camera, but that’s not saying much.
I learned a lot more about composing and taking photos after getting an old manual film camera when I was in high school and just shooting on that around the house, my neighborhood, the town, on vacations, wherever really. I made a lot of bad photos (and still do!) but I still think that’s the best way to learn.
So my advice to you is: if you haven’t already pick up an film camera that doesn’t have any automatic settings, get a few rolls of black and white film, and just start taking photos. As you shoot you’ll start to get a feel for how exposure, ƒ-stop, and ISO are all related, not to mention how to compose a good shot. Look at lots of photography that moves you, and really ask yourself what about the photo makes it “good” in your eyes. Dissect the framing, the composition, the subject matter, etcetera. Pick up something like the Exposure-Mat (or my forthcoming app, Lghtmtr *wink wink*) to help you from taking completely terribly exposed photos at first.