@Hasya New series published on Ganma are free until the end of it's serialization. Premium user can read 1 chapter ahead compared to free user. Series only being premium walled if it already finished or it's a series from another magazine being published on ganma for limited time.
I checked ch1 on ganma, it's basically a reboot and there's some new stuff too.
As for supporting the author, you can watch a video ad at the end of chapter (3 max perday), give them coin (similar to ko-fi but using in app currency) or simply press the heart button at the end of chapter. I've seen some series being axed from not having enough hearts do make sure to smash that button.