Remember, you must seduce the woman.
Just because you had a good interaction and got her number, does not mean she will be up for a date. She will generally only want to meet up with you if :
-she trusts you to some degree
-shes attracted/mystified to/by you to some degree and wants to know more
You had both of these on the night you met her. So you need to keep this up until the next time you see her. You accomplish this thru solid text and/or phone game.
Shes not gonna respond positively to "hey when are you free? lets meet up" texts all the time. She may, but it wont be fun or exciting for her.
Your phone game sux, so you must text.
When she texted you on that night, it was a perfect opportunity to demonstrate what you got. I would have made it something like this:
Her : Hey!
Me: Hey! Where you at?
Her: Just left the art show im pretty tired

. Where are you at?
Me: Im at bar @. I feel like i might get murdered here though.
Her: lol what why?? Im so tired im going home
Me: i was only kidding. your silly for believing that. if you were here i wuold make you take 2 shots for being so gullible.
Her: lol blablabl im a silly girl ablablabablabl
basically you dont react to her comment of going home, nor do you even ask her to come out. instead you amuse yourself by making fun of her or busting on her somehow. this sparks attraction and interest, and doesnt classify you as just another guy who wants to meet up with her to (ovbiously) get into her pants.
she will then be thinking " wtf he didnt even ask me to come. there must be other girls there" etc etc . she will be wondering. always keep her wondering. you need to set up this frame before meeting up with her. trust me it will make the meet up 100x easier because by then she will be DYING for you to make a move because shes super attracted