I would personally prioritize seeing Part I before Part II. Part II perfectly compliments Part I. If you can’t, read a synopsis of Part I on the internet so you have an idea of what’s going on in Part II.
"Mostly, I loved the size of these people's emotions. Nobody has emotions this size anymore. Outsized emotions. Operatic emotions. Kushemski and Vanda are like Tristan and Isolde, they're Paolo and Francesca. Nobody's in total thrall like this anymore. Nobody's overcome by passion like this, or goes through this kind of rage." Thomas, Venus in Fur