Dear future tushar,
dont do a startup or think of becoming a millionaire just to become a millionaire, bruh focus on becoming the best in your field, if you dont have a idea right now its ok, improve yourself and get better at coding and public speaking and enjoy the things you are currently doing in your life, remember all the great things were not a result of forced efforts they were a result of spontaniety. you are always thinking of just becoming financial independent and cracking the entrance to get the best college, yeah they are necessary to think about but dont do just to achieve the goal, do maths to understand maths, learn chemistry by taking it as a challenge, and you love learning more about physics and remember life does not not goes with your plan, so dont plan and waste your time fantasizing about stuffs and i know saying and writing it is very easy for us, but we gotta do it, we cannot waste most important years of your life just thinking and fantasizing.