The conception that you have one " element " is wrong. You are all of them, for nature is all of them. Both creative and destructive.
Now if you mean which element you feel most drawn to, or if you are, by any chance, asking which ' element you are ' accordingly to your birth date, that's something different. For example, there are fire zodiac signs and the same for the rest of the elements. These are two different cases.
If you feel drawn to one element in specific rather than all of them, it is normal. But it doesn't, by any means, mean it is " your element ".