(Warning: Minor Spoilers follow)
Minor spoilers follow, so if you wish to not read what could be crucial details, please back away now. Here is what to expect in Season 2.
As per the details of Season 2, the number of episodes will be relatively shorter - probably an estimate from 8-12 episodes. The timeline will take place 3 months after Season 1's finale, which will take place early June 2016, around the time when Psycho Kid Kills Father would have been released. All the episodes will be released all at once (maybe the finale episode will be released at a later time) in similar fashion to Netflix shows.
In Season 2, it will be made clear that our protagonists aren't kids trying to make a difference anymore. They - prominently Oscar Miles - are becoming young adults who are trying to fit into modern society while facing the struggles of the aftermath of Season 1. Ever since the to-be-revealed finale, everyone is pursuing differing philosophies, which ultimately causes a rift between past friendships. The legacy of The Lomax Murderer, whoever he/she is or if he/she's dead or arrested will haunt Miles regardless and will have a big effect on him. Whether this effect is good or bad will be revealed.
The stakes in Season 2 will be relatively smaller. So if you don't like the murderous tone, then I'll think you'll enjoy Season 2 more than Season 1. But Season 2 will also try to impress the audiences who did like the horror direction. Fortuna Academy is also scarred from the events of Season 1, hencing rise to enemies old and new, including Psycho Teacher and Dylan Stryker, alias the Rock N' Roller. And then there will be one more mysterious enemy who will be the big bad of the season. There will also be a new set of protagonists and supporting characters. As of October 9, there are five new heroes. The number of teachers will also increase.
Season 2 will be released sometime between June 26 - July 24, 2017.