It is not necessarily the real birthday of your new girlfriend. It is just to test you to see if you are good enough to say what you said. Of course, it is also very likely to be her birthday. In short, it is necessary to choose a good gift. Here are some suggestions for you:
First, give her a slightly more formal gift. After all, this is the first important day of your relationship. It is very good to give her a beautiful ornament, a pendant or a necklace.
Second, give her something for girls, such as perfume or cosmetics. Of course, you will not know her preferences very well at the beginning. You can ask her about it, which will also promote your communication and mutual understanding.
Third, give her a creative gift. You can choose a crystal music box. The beautiful style and beautiful music will attract her. You can also buy a bouquet of roses and give her a box of DIY chocolates. Make what you want to say. It will surprise your new girlfriend and she will also discover your romantic side.