How can i get this girl?

Hey guys, i need some help with this girl. Alrite heres everything. Were juniors in HS. Friday is our last day before finals. This girl i've liked is really quiet and only talks to a few other girls. She doesnt talk to any other guy at all, NONE. shes really cute and i really like her. We've never had a ongoing full conversation before. So last friday, knowing the end of school is coming and being uncertain about us having classes next year, i decided to grow a pair. After the bell rang i walked up to her and said "hey {name}, i know we never really talked, but i was wondering if you were doing anything this weekend." she said "Oh, yea.....sorry" and walked away. I felt like trash the entire weekend until i learned she actually did go somewhere with her family. This girl is REALLY quiet and shy, so if i want this i'd have to do it all. My mind is telling me to just move on, but my heart wants her so bad. Can someone please help me???