Just check this schedule out, might help -
9th Grade--
- Focus on Grades
- Involve yourself in different clubs and activities. Don't go for quantity, just try to be active and do something significant in a few.
- Get SAT/ACT books by the end of the year, and start preparing in the summer, just lightly.
10th Grade--
- Boards year! try getting really good in boards. Main Priority!
- Maybe take the SAT or the ACT once in like October/November in 10th. Just for understanding, but give it your best.

- ExtraCurriculars!
11th Grade--
- Internal Marks! 11th Are the most important scores. Try getting 85%+
- Start thinking of what you want to major in and maybe get yourself familiarized with the process of applying and all that.
- Take the SAT or ACT again! This should be the time where you aim to get the best score. Don't wait for another try.
- Extracurriculars!
- Towards the ending of the year, start looking at colleges and maybe through the summer and finalize your list before 12th starts.
12th Grade--
- Boards year! Do really well in Half yearly exams!
- Start working on the essays maybe in June-July. Don't postpone.
- Take Subject Tests in June or October. If you are confident, then take them in 11th, but they usually include some 12th portion too (For Sciences, as for as I know.)
- Start Apps!