Sorry my bad. It just looks like you were born in 2016 then your Minecraft name is Ninjakidz2016 and your grammar also makes it look more like you were born in 2016. But i could be wrong and i choose to trust you then you say that you are 15.
You should wait some time for applying for staff because youre forums account are made on April 27. And if i guesses right you are only like 7-8 years old (you have to be 13 years or older).