How do you stay focused for long periods of time ? And how can you maximize studying absorption?

Take a lot of small breaks. You can use for exemple the pomodoro thechnic. Altern between 25 minutes of deep concentration then take a break for 5 minutes . Repeat for as long as you want.

Personally I use my will to intensely concentrate or direct my awareness on what I’m focused on studying, memorizing and absorbing or doing. Being able to do it for long periods of time requires consistent effort and practice. When I will to quickly memorize something, I use my will and awakened heightened awareness to capture the moment or information by intently or fixedly focusing on it until I can clearly see it in my minds eye and I’m easily able to recall at Will. It gets easier with practice.

Study the subjects you like would help. If thats not an option, then just keep the goal of hugh grades and not getting in trouble in mind. Also, studying for 25 mins intervals with 5 mins breaks for water and stretching helps. But do not go on social media or anything like that.

In studying repetition is key I like to normally type up my notes or rewrite them to go overthrow information and then I create flash cards or quizzes to make studying fun while learning the material. I also make sure to take breaks in between to maybe a take a shower or get a snack to clear my mind and then I come back to it see what I know and go from there.