season 2 ?
will these show have a second season
or it ended with these 14 episodes
Season 1 has 12 episodes only, plus some OVAs that are out/will be out, you can check the list here:
https://en.wikipedia.org/wiki/List_of_One-Punch_Man_episodes
Although it's highly likely that it will have a Season 2, it may only premiere next year, or maybe in 2018, it's unknown at this time.
You can always read the manga (not much development, but still a fair bit after what we saw in the last episode), or the original webcomic that has already covered what would be the 2nd season of the anime.
Fine, fine, I'll leave! But first I'm going to bother these peanuts! Hmm? Yes? Hmm? HMM?