Study Plans for homework, SAT, and AP exams

Hello everyone. I’m going to be a junior this year and I’m really worried about my study plans. I know it’s still early to think about it, but it’s going to be tough. My study plans before were studying for 20 minutes for two classes everyday. But I don’t think that’s going to work anymore. I’m planning to start studying for AP exams around midyear and plus I’m planning to take SAT in March. On top of that, I have to study for classes and tons of homework. How do you make plans for this? I don’t think studying 20 minutes for each of them doesn’t work anymore it’s too much. To those who went through this, what were your specific plans? Thank you so much!