How to study physics and chemistry for neet? what are important topics? which tricks help us?

First you need to make a daily schedule. Study according to the schedule regularly. Go through the  whole syllabus. Choose best books for preparation. One of the greatest tips to crack NEET 2020 can be referring to the best possible books that can help you crack the NEET. Other than NCERT, practice H.C. Verma and D C Pandey For physics.
In Physics, Electrostatics, current electricity, Electromagnetic Induction & Alternating Current, Motion of System of Particles and Rigid Body, optics, thermodynamics etc.
In Chemistry, Solutions, Chemical Bonding and Molecular Structure, Thermodynamics, Equilibrium,
Coordination Compounds etc.