how do you trigger the state events?
This guide should still be accurate. For each girl, in their "<name> scenes"-spoilers, the entries beginning with
(State) describe their state events. The "State Events + Q&A"-spoiler also describes how to get the different outcomes of the state events.
EDIT: Forgot to actually link the guide. Great work, me. Fixed it now, though.
Lucile being clueless of what sex is might be interpreted as she not knowing what she was doing (stupid, I know) since there was also no indication it was her first time.
As for Vera, she mentions a boyfriend she had at some point and that the MC cums far more than him but it isn't explicitly expressed if they had sex (from what I remember), but I'd guess she's not a virgin either.
The reason I wrote in my previous post that Lucile is most likely a virgin was not solely because she seems clueless about sex, but rather wider observations regarding her reactions to it. Even just touching Lucile's vagina appears to have her react as though this is an entirely novel experience, with the possible implication that she has never even masturbated before, and upon actually having sex there is no indication that the experience is in any way familiar to her.
The lack of the typical indications of it being her first time - that is, bleeding and pain - is most likely either a stylistic choice on Bones' part or just him being cautious because he wasn't sure which scene with penetration would come first and did not want to risk any awkwardness with her losing her virginity repeatedly. Allowing a little benefit of the doubt for the writing, it could even be explained away with Lucile having been born without a hymen, or having broken hers during other, non-sexual activities.