Dear Preet,

JEE Main is one of the competitive exam. You need to work hard to score good marks in JEE Main. 
To score good marks in your exam it is very important the you have good hold on P/C/M subjects. You should have your basics strong. Take NCERT help to work on your concepts. It is very important to solve all the exercise given in NCERT book you can also go for NCERT exemplar.

Practice makes lot of difference specially in mathematics. Try to give extra attention to important topics which carries more weight-age in the exam. You can also solve MCQs. Solving complete mock test series is very important make sure you do proper analysis. So, that you can improve your performance. It will help you to know where you stand among other competitors. Try to increase your speed as well.

All the Best for your preparation and exam!!