Is it possible to become less shy?

Well i was at work... I'm 17 btw... I push carts at a grocery store... And I find that degrading As it is but any way i saw a very beautiful girl... We made eye contact and smiled at one another multiple times and as she was leaving I told myself I would say somthing to her ask for her number or somthing but.... I couldn't do it idk why I had every intention to but I froze i guess inwas just wondering if anyone had any advise please and thank you..