Use and agenda or planner to keep up with your assignments, quizzes, tests, and projects (digital calendars like Google Calendar are great options too)
Ask questions when you have questions, do not wait until the last minute or after a test to ask a question about the material
Take advantage of quiz/test reviews that the teacher provides (they are providing that information because it will probably show up on the quiz or test)
Get enough sleep at night! It is challenging to stay focused and on task during school if you are tired!
Designate a space or area in your house where you will do homework and study
Plug your phone in on the OTHER side of the room, so you can work and study without distraction