i see RPGM but is this game divided by "chapters", like very update you progress a little in the Main Story, are there Side Quests? do you have free movement through some parts of the content?
This game isn't divided into chapters. You have access to most of the map from the start (although there are obviously many areas locked behind quests), and your ability to explore that map and complete quests is mostly limited to how strong your character is. Each update just adds more quests and sometimes characterd that come with those quests.
There aren't really "main" and "side" quests; there are mandatory quests and optional ones, but the divide between them doesn't really feel like that. In other games, the main quests advanve the actual plot, and side quests are basically diversions, but in Peasant's Quest, each quest progresses your relationship with the person or faction involved, and there are some factions that are more important than others, but really you probably want to complete all the quests in this game regardless.