You have to keep doing the dates over and over again. Work your way up to the Theater date, and always pick the Musical option if available (its her favorite), when youve worked up to lunch pick Sushi since its her favorite food. Fully pay the bill if possible. When youve finally worked up to the second part after lunch, you could go anywhere, but I'd recommend the Library since it has a book topic check (lets pick eachother's books) that could get you more points.
Side Note: The game says a certain stat helps boost Vibes as well. The Hotel and the Clothes Store both give 2 star and 3 star gains towards that stat respectively.
The real pos is getting her to talk about her private shit. I assume it happens at certain checkpoints on her love meter, but hell if I know when exactly those are. The point is, by the max of 300 love, she should have given you all three talks. If she hasnt, simply keep going till she does. Don't be surprised if you get over 700 vibes on a date only for her to talk about you not having a gf, it happened to me as well. Just do one or two more dates and she'll follow you back to your apartment. Hope that helped.