Before we assemble the headjoint to the body of your flute, take a closer look at it. Notice the rounded cap on the end nearest to the blow hole? That is used to tune the flute. Since your flute is probably already in tune it would be a good idea for you to leave that alone for now.
The relation of the blow hole to the keys is important. If you misalign the hole, your hands will not be able to form a good playing position because they will either be reaching over the flute, or they will bend backwards.
For most players, aligning the back, far edge of the blow hole with the center of the keys is the best position. About one in four players will be more comfortable with aligning the center of the blow hole with the keys, but for now stick with the far edge.