The first fanfic I read was Harry Potter and the Methods of Rationality. I read it in early 2013 on a whim after hearing about it by chance in a news story. After finishing it (it's great by the way if you haven't read it) I started reading more Harry Potter fanfiction, and then moved into Naruto as well. Recently, after reading some stories that made me truly angry with how much potential they had, but how annoying they were to read, I've started thinking I want to write my own story. If I do, I will probably start out with some one-shots at first to 'test the waters', so to speak, before hopefully moving onto a longer story if I can find the motivation and skill to do so.
I can't believe I didn't get into fanfiction before I did seeing as how much I've come to like it.