Chhava for a keralite

As the caption suggest I'm a Keralite who wants to watch the movie Chhava in theatres so this post is to the ones who knows about the maratha empire and all I don't know anything about maratha empire, shivaji maharaj or sambhaji Maharaj the only thing I know about is that Shivaji Maharaj has played an important role in protecting the early day bharat from mass conversations, invasions and has protected many temples even in Kerala from mughal invadors So I wanted to have a backstory of things to basically understand the movie while watching otherwise it'll be an utter waste of time so please anyone tell me some basic information to watch the movie