Few important things I want to share-

Be attentive during classes whether tution or school, trust me most of the time the lack of difficulty in understanding the concepts arise from this only, focus and concentration during this study time makes job easier, later on you can just revise or go through the chapters. I know, for a commerce student, a lot of depends on practice as well.

Devote time to each subject accordingly, perhaps the difficult one a bit longer compared to the the one you excel in. Also, do no study for more than one-two hours at a stretch,because sometimes too much of study takes a toll on brain. You do not have to feel stressed out, in fact make effort to enjoy your study.

If you're an early riser, then you can spend few hours in the morning for study before school, if that seems convenient for you.

If not, then you have few hours of free time in between your school and tution, you can either revise for what you have studied in school, along with go for another subject you want to study.

Lastly, your free time at night, you can revise what all you've studied at tution(Accountancy) and at the same time you can study for another subject as well like Economics/ Business Studies.

See, nobody can prepare the exact timetable for you, because you know the free time you have, also the time which suits you for study, subjects you find interesting or boring,not everyone is early riser, so the change shifts accordingly here.