I'd probably stop time in the morning before school, do some stuff and then run to school and unfreeze so i'm there instantly
Why even go to school?
When you are the divine overlord, controller of time and space, I'd imagine you would have little need to keep your school attendance up.
Assuming I don't age when time is stopped (not really necessary but cooler) I would learn a load of stuff like flying planes and kung-fu, also become a super hero/villain, fighting champion and magic man~
Also I would pause time every time I slept so I could wake up again as if I had never slept in the first place.