Nodutdol, an anti-imperialist group of Korean ex-pats, released a toolkit for better understanding the ROK and DPRK, as well as Japanese colonization and the US Empire's role. There's good resources there for beginners. Kim Il Sung is highly revered, and the Kim family is respected and loved. It isn't a "cult of personality," though, that's a misframing of how the DPRK functions.