I am a University student, last year of Masters. In University we can get 50% cheaper transportation pass for bus, if we apply. I forgot about the deadline but the girl, also a student, who handles selling these passes in University, sent me an e-mail to remind me about the deadline. She had my email address because we have to apply via e-mail.
It's such a small, but nice thing to do. I replied - thanks, do you like chocolate?
I know, it was blunt, weird, but this approach seems to work for me more often than not. Questions out of the blue, bordering with stupidity. Kind of my style.
She replied - "no problem, glad I could help. Sure, I do

"
So I brought her chocolate when I arrived in person to pay for the monthly transportation pass. She was alone. I made some small talk, about me being forgetful, made her laugh. Gave her the chocolate in the end. She said I did not have to do that.
Today I went there again, to pick up the pass. She seemed busy, other people were waiting in line. But she just kept smiling.
What does she think of me? A cute guy who gave me chocolate? And shows not much interest otherwise? Hmm...
I don't think I am in a bad situation now. But I don't know how to find out if she has a boyfriend, and how to ask her out. Found her on facebook, looked at her pictures. No obvious signs of her having a boyfriend. She is 22, I am 26.
I don't know how to proceed. I don't have an obvious reason to go to her office now, and I think asking her out via Facebook or e-mail would be inappropriate. Yes, I considered that for a minute. Scrapped the idea.
I plan on a meal in cafe, nothing fancy.
Any advice, gentlemen?