If you're getting 8-9 hours that's a pretty reasonable amount. Personally I'm more of a early-to-bed&early-to-rise person (except for getting late shifts at work) and I generally feel better when getting 2-3 hours sleep before midnight.
If you have enough energy to complete your planned training, then you're probably getting enough rest. Being in high school probably means you're still pretty young as well, & I reckon you can get away with a bit more rebelliousness at that age and still train well compared to when you get to your 20's.
No hard and fast rules on it. Everyone is different and the only answer to how much rest or sleep is necessary is "enough".