On her B-day, get her a cheesy card, like"You are the only blossom in my life!!!" With her favorite flowers(find out what her favorite type of flowers are) and heart chocolates!!! Or get eleven real roses, and one fake one and say" I'll love you until the last rose dies," which will be NEVER!!!! And it will still be a bouquet!!!
It totally depends. If you barely know her, but just like her, then I would NOT buy anything. Instead talk to her, more importantly listen to her. Get to know her better... then you will not have to ask what to buy her or where to take her on a date b/c you will Know.
I would get to know her better and just talk to her when you both are alone. So you can focus just on her. Then ask her to a movie. As far as gifts? Flowers, stationery, card, chocolates, or a nice candle! Good Luck! :-)