How much should you know about a musical before you see it?

Possibly a strange/stupid question, but I only started getting into the theatrical world last year (grew up conservative with a pastor who preached entire sermons against theater. Long story) so I genuinely don’t know the answer here. I’m seeing Little Shop of Horrors at the end of the month as a gift from my dad, and I know almost nothing about the plot, the characters or anything besides “murderous plant.” I have a friend who’s offered to send me a video of her college’s production from several years ago if I want some background, but I don’t know if it’s better to go into a show with some knowledge of it or if you should go in completely blind. I’d love some opinions on that if anybody feels like offering theirs!