Am playing chess for last two years. I am trying techniques like controlling the center, not allowing week pawn structure etc. Now i am trying to build up an opening repertoire . my question is where to start? which openings should be checked first? Any techniques there for memorizing these openings. 

if i study some openings and its variation, will that help in memorizing other openings? ie. is there any patterns exist in these openings? Glad to hear from experianced players soon.