I went through a summer of running about ten years ago when I ran many 5ks. Thats it. No history of playing sports at any level. I've followed training plans religiously this year and that helped "do it right". My first half marathon was using Nike Run Club which is fantastic because it "teaches you how to run". My next plans were with Hal Higdon and Garmin.
I'm starting this in my late twenties after a fairly inactive decade; hiking has been the only thing that's kept me active over the years.