Can anyone give me advice on how to talk to a movie cashier I like?

So, finally, I get my braces removed, so I decide to see Bruno afterward. I go to get my ticket and here is this beautiful cashier. Now, im weird, and many girls don't catch my attention, but this one did. I'm a sucker for eyes, and her's were just lovely. I just don't if she gave me those eyes, or they're like always like that. How can I talk to her; I am very shy and I either blush like theres no tomorrow, or I stay quiet and use as minimal words as possible, which i stupidly did..... If I have had blushed, at least she could of know I like her and maybe things could of gone from there.... Oh, one more thing, before I went to buy the ticket, I went to a convenience store to buy some snacks, which is next door to the theatre. I saw her looking my way! Could she just be looking for customers, because the place was empty. I did park at the theatre parking lot which is in front of the cashier window, and I would have had ped her field of view before getting some snacks. Did she have an interest in me? Why cant women be more straightforward?!?!?!?!?!