Hello there! There is in fact a guide you can download on the itch page that will give you some hints (and if you scroll right to the bottom, the outright answers) on what to do. Stat raising is there for the sake of having some gameplay, but I know it's not for everyone.
As for free or commercial, a little of both! You can play up to September in the demo and up to October if you support me on Patreon. However once I've finished November and December I'll start releasing chapters publically, for free. So the patron thing is more like early access!