If you are wanting to do elemental spells, you need to take some time to first learn about the elements and all the basics to magick first. And as it has been told to you, not everyone has a certain element and it doesn't always connect to horoscope ones. However, I have found that people tend to be more in tune with certain elements than others. Mine is water by horoscope, but I also do connect well too it on a level that I can't explain. Because of this I do practice sea witchery. But I only started this after practicing using all the elements.
Here are some books you might want to look into:
-Earth, Air, Fire & Water by Scott Cunningham
-Earth Power by Scott Cunningham
-Elemental Witch by Tammy Sullivan
-Elemental Magick by DJ Conway
If you can't get a hold of these books, becareful what you find online. There are lots of sites with misinformation. Always use your common sense when looking into witchcraft topics.