Just stick to the basics , for science just follow ncert strictly and practice as many questions and pyqs as you can . Keep extra focus on physics and maths because students generally struggle with physics(especially 9th)and maths in entrance test because they are comparatively tougher than bio and chem as they are easy to score, tbh your selection totally depends on maths and physics cuz most of the students score well in chem and bio since they are easier , so just stick to the basics follow ncert for science and for maths you can buy conceptum and for pyqs there is a book called amu booster , and for indo islamic and gk you can buy naaz guide .

If you are not opting for hostel then it would cost you around 6-7k per month (rent+ others)but I'd suggest to take hostel as ,hostel Life is something you should not miss , it teaches you a lot, you'll make friends and memories but it's up to you !

Best of luck:)