I go to school on foot.
I have to submit an absentee notice to my school, so can I have one, please?
Why are we barbecuing hot dogs at school during class today?
A study school is obviously a place where people study and learn. In English, that's simply a school.
This jukugo word consists of on'yomi readings, except 学 (がく) is shortened with a small っ to make it がっこう.