Actually, the idea that you have an Element isn't correct. It's something that Hollywood dreamed up in the movie, The Craft, and someone people latched onto it and it won't go away.
We are not one Element, we are composed of all of the Elements. What we truly want to do is learn to work with all of them in balance. It is true that you may find that one or two of the Elements are initially easier to work with. That isn't because they are "your Elements" but because you need to spend more time and effort learning to work with the others that are more difficult for you.
Nor is it true that "your Element" is the Element of the Sign of the Zodiac in which you were born. Anyone who does astrology can tell you that your birth sign is only a portion of what influences your life. Which Houses the other planets fall in also has great influence. Take myself for instance, I was born in Taurus, which is an Earth sign. But I also have planets that fall under Water, Air, and a lot in Fire. So again...I am not one Element only.
Which Elements you work with also depends in part on which forms of magic you practice. The classic Elements in Western magic are Earth, Air, Wind, and Fire. Some also add the Element of Spirit to that. In Chinese astrology and magic the Elements are Metal, Water, Wood, Fire and Earth. That's why it is important to understand what you want to work with and in which system you are working because it changes the perceptions regarding the Elements.