It will have some sort of '行动力' system, you are given a certain number each day, which lets you go out on certain number of missions (some low level missions will cost 0). Once you used up, you either have to end and wait for next day, or you pay real world money to buy gems 宝玉 so you can continue playing. The gems will let you buy/draw items like 御魂 in-game too. You can only play story mode till mid chapter 1. The f2p version can play together with the full version owners. Your f2p progress can also import into full game, so just consider it a demo to try out without spending any money.
You can pre-register now to get 5 gems when the f2p game launches. Looks like it's Traditional Chinese only.
https://blog.asia.playstation.com/hk-chs/5196/2017/02/基本免费之『讨鬼传2-共斗版』繁体中文版-于ps-store开始/