How to best learn opening variations (techniques)

How to best learn opening variations ().

I do not play chess long..maybe 4 month now and i start with queen gambit for white and king indian defense for black and i will stick for that for a while cause they look so much fun I use to finding variations on you tube  and try to watch them ,,remember ,,get some playing then from time to time go back to old videos and watch again..doing that over and over .That is my way of learning so i curious how others players learn variations and openings....maybe is there some better techniques so please share...i want to get better.and one more thing....if you could post some variations for queen gambit and how much variations this opening has?

Thanks for help

Regards Nettrick