Hello dear, 

Jee mains chemistry questions are not difficult .Chemistry section is always scoring. Most of inorganic questions and physical chemistry questions  are directly asked from ncert, so you should blindly follow ncert .Some questions are directly based on formula. For organic chemistry ,you should remember named reactions and reagents. 

Beyond this you should give regular tests to increase your speed and accuracy .Make hand written notes and go through concepts and practice the numericals of ncert(must).

Hope this helps you. 

Good luck