Sorry it’s so long, I felt some of the background details were important and I really don’t wanna mess up.

We’re both freshmen in college, but back in middle school, I would hang out with her occasionally, which was so long ago (i know). Her friend later told me tho that she used to like me back in freshman year of HS so at least I have that info to work with. In HS, I never really got close to her though and in senior year, she asked me to catch up with some other friends so we got lunch one day. She had a bf then tho and she did up until a few weeks ago. I heard from my friend that goes to her college that she broke up cuz she wanted to meet more people and not be restricted (sounds like a bad reason i guess but ur also not obligated to stay in a relationship if ur not happy) She told me she might come visit my college for a Halloween party (we go to different colleges) so I said cool and that was the last we talked. Today, she posted a pic of herself in a dress on snap, and I was thinking I should reply “that dress looks great” or something and then be like ur still coming for halloween right? Or should I just message her the halloween thing and not respond to her dress pic. I’ve never made any move with her cuz I’m SUPER shy so even thinking of msging her “you look great” would be way out of my comfort zone, but I really want to make a move so something can hopefully happen when she comes over. Any ideas on what to do from here and what message I should send or if that’s a good idea?

Thanks SO MUCH if you read all that, thought most of it was necessary for context