I did a cold approach on a girl at the mall's door the other day. I straight up went and said "Hey, what's up?"

She said "I'm fine you?"

I said "I'm fine. Hey, wanna give me your number?"

She said "Why?"

I said "I think you're really cute, it'd be cool to go out sometime".

She said "I can give you my facebook, you got something to write on?"

So then I pull out my cellphone and say "Here, do you know how to write on a cellphone?" We both laugh, she's kinda nervous and shy.

I proceed to laugh since she couldn't write down her complex last name and I wrote it down myself, said a goodbye with some eye contact (she looked down) and went my way.

I added her the next day and she accepted me today.

Now for the grand question, how should I proceed? I was going to go to a free concert at the beach tomorrow and I thought of sending her a message like "I'm going to the concert at 3, see you there. Bring a friend if you'd like" - Since I might go with a few friends of my own too.

Problem: I don't know if she likes the band or not... So she might say no.

What would you guys do?

P.S: It was my first approach ever... Felt great.