One has to understand the basic princiles of organic chemistry first. These include : A} Fission of bonds and reaction intermediates with their formation, stability , geometry , and reactions which they undergo. B} Nomenclature without which we will not understand which compound is referred in the question. c} Isomerism including stereochemistry. D} Types of the reactions.

Each class of compounds gives typical reactions which are the main reactions like nucleophilic substitutions in alkyl halides ; in some topics we can classify the reactions in catagories like in alcohols reactins given by H of OH, reactions given by OH and the reactions of entire alcohol molecule. Like this while studying each topic you will come to know about the reactions. Instead of memorising try to understand the reaction know its mechanism stepwise reaction.

NCERT books are very good first books to begin with, once you are satisfied that you have followed the topics go to other books. Don't jump to higher books , always slow and steady with patience and practice you can master organic chemistry.