What do I do now?

Well, I'm looking for advice ,
I met a girl at a party and after the party she got my number from a mutual friend and messaged me, saying so. So, I asked her out for a coffee, she told me sure , she's got time ( FYI both in Uni) and we fixed an appointment. On the day of the appointment she told she'll be coming along with a few colleagues/ RAs so I said sure. But on meeting, she didn't say a lot and I spoke a bit with her colleagues and we just split after that. So... What did I do now? Do I write to her again? Or do I just leave it at that?
What do I do now?
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