Although I try not to label a situation as a date unless one of the two people involved explicitly used the word "date," this situation does sound like a date. "Dinner and a movie" is practically a generic description of a date.
So here's how I would handle it if I were in your shoes:
Offer to pay, but don't adamantly insist on paying. If she lets you pay, that moves this evening into more definite date territory. And try out a mildly flirty remark, and see how that goes over. If she doesn't react badly and doesn't suddenly mention a boyfriend or fiance, keep going with the flirting. If the evening does include a trip to the bar towards the end, see how she acts after a drink or two. Alcohol isn't a truth serum, but it is harder to keep reactions and agendas hidden when drinking. Of course, that cuts both ways, so you might blurt something out. Anyway, if the flirting has gone well, you might try moving on to touching at the bar. Like touch her hand lightly when you say something funny. If she touches you back, that's a good sign. If you play your cards right, you might end up going back to her place, and you should know what to do from there. At the very least, try to get her to let you escort her home, and then try for the kiss there, but only if the flirting has been going okay.
Good decisions come from experience. Experience comes from bad decisions.