I think It'd be better to read from where the manhwa left off ╮(￣▽￣)╭
It's a rare case where the manhwa doesn't skip anything and is very faithful to the novel, u can start from where the manhwa chapter itself
i suggest to start from when they win the contest/when the group was formed. after that, i noticed several changes in details like some parts being shortened or being skipped and those are good fluff. i think there's nuances that wasn't captured anymore in the manhwa. the plot also in the novel gets more complicated after the contest and that's where you get to know each members characters and personality more based on their interactions with each other. so it's nice to start there. until now, we only see bae sejin here (the actor) as like a minor side character while his character truly shines in the novel enough for me to like him almost more than ahyeon.
There are stuff that was not in the manwha.. so just to be sure, start it from the beginning.
if i were to read the light novel , would it be best to start from the beginning or start where the manhwa leaves off ??? (⌒▽⌒)