my first direct open...story and questions

here's the replay:
I went to supermarket to buy something. I saw a single set of 6, after I decided to approach, I found a group of people stop right beside her, and she was picking the goods on the shelf. I couldn't find a room to stand beside her to say hi, so I just gave up.
a few minutes later, I met her at another spot in the supermarket, so I go up directly and said: "Hi, I just walked by and saw you, and I think you're a pretty girl, I can't help coming to say hi to you..." she looked very surprised and like don't know what to do, she even dared not to give a eye contact to me. when I held out a hand and want to introduce myself, she didn't notice that and walked away. I thought I blew up.
But, when I waited for paying at the counter, I saw her coming out and come up to my line, stoped right behind me. so I said hi to her again said I meant nothing but just want to know you. she was just like a shy and said nothing. then I gave up number colse and left.

my review of this first direct approaching:
Pros: I delivered the Opener just like I planned, I thought the tonality was not bad. and I'm confident, more, got a score of killing aa.
opportunities: body language should be more natural, need less hesitation, improve the flexibility during the approaching to adapt to any unplanned situation.


hey, seniors. I got 2 questions after this:

how to find a right time a right spot to approach? did I do right in this case when the first time was not good for approaching?

what I can do if the set is too shy and shocked to give any response and just walk away. what should I do to follow up to # colse without acting try-hard?

My past messages have been about this..the SHY types. I just had to say forget it after a while. Sometimes the silence seems to be even MORE brutal.