Anyway, advice? Read, alot. Corrections: Except*, which*, probably*, and you always capitalize the letter "I" when it's the word "I" or any of the following: "I'm, I'll, I'd, I've, etc..."
I'm 16 years old too, where are you from? I think that you need to read English, if you want your English to be improved. I think reading does a lot to a man's language, and it is irreplaceable .