Does she have an interest in me? What should i do?

While to work the air condition repair folks came to fix our ac(a male and a female). Our door needs a swipe to enter so i had to swipe them in. We were in a work meeting so i pointed them to the ac and went back. The female then came to the door and pulled me by my arm(i was in the doorway and not in the room) and asked if i can let her out, i gave her my badge and told her use it. So when the meeting ended i was heading out so i went to get my id from her in which she called me by my name and smiled when giving it back to me(name and photo is on the id). Fast forward now, when they were leaving i didn't buzz her out and she laughed and asked if i didn't want to let her leave. And i said i want you to stay jokingly of course. She then said but you don't know my name so i asked and she told me but didn't get her number. So i added her on fb and said hello , she then gave me her number. Where do i go from here? I'm not the greatest with relationships or else i wouldn't be on yahoo lol