I got her number... but whats the use!

Yeah! i got her number... talked to her today after my training and i just pop-ed the question!
the courage i took was like asking the girl to marry me! it was kinda hard at first... but i just asked. "hey, do you think i can get your number?"
pretty girl says, "yeah sure my number is ********, just drop me and sms and i'll know ur number"

well, i did sms her... i said "Hello, this is andrew... see you on friday for boxing. take care and have a safe journey home. Night!"

its like 11.30pm and she didn't reply me sms!!! ARGH!!!
I feel kinda shitty when i ask someone for her number and yet she doesn't reply me! its like... i don't know if she finds me irritating...

What the use of having her number when she doesn't reply you.. its kinda shitty man...
What kinda stuff can i talk to her about anyways?

PS: i need help in conversation with girls....