Should i make a move?

Ok, so. I have a huge crush on a girl. This girl was infatuated with my best friend but he hated her, so she's now over him. I'm falling for her. I told her how i felt and she rejected me, due to the fact that she was still in love with my best friend. They're now friends, he told me that she is getting attracted to me. Her and i talk to each other for a good 3 hours a day and more at the weekend. I don't know what to do. Should i ask her out... Again, i don't know what to do. I'm 15 male from UK. Any help? Xx also, any advice on what i should say would be great. X