Just a quick thought, I'd hold off on the "girlfriend" label until quite a few datest later, when you two are exclusive and you actually know each other in "that" way. No rush on the labels, they just complicate our relationships.
On your first "date" together, keep it simple, nothing crazy or fancy. A really fancy thing will make you look desperate (again, this is in today's society - years ago that may have been more appropriate). Maybe get together for a coffee, go do something fun together like a concert, something like that.
They key point is to find an activity where just the two of you can spend time together to get to know one another and see if the chemistry is there. That's why movies aren't good as a first date, because there's not much interaction.
Then on the second date and other future dates, just keep it fun and interesting. Do different stuff, not the same thing every time. People want to laugh and be happy; make them feel happy, they'll love you for it.
Check out this date ideas guide from our friend Michael Webb with hundreds of great - and unique - date ideas. Remember, keep it fun and unique, nobody wants to go to the movies every weekend. LOL