Fighters are easy. Just takes some research, a lot of practice, and being okay with being bad for a while. Cause you will be, for a while.
Another big part of it is finding out what kind of fighters you like cause few people like all of them. I, for example, am not fond of 3D fighters (i.e. Soul Caliber, Tekken, etc.) and I'm not really fond of games that have block buttons (I'm looking at you Mortal Kombat).
A lot of people I feel don't take this into consideration and try one fighter they dislike then drop the whole genre.