I’m a 15 year old girl and I have been playing guitar for a couple of years now. I have never taken lessons so it is possible that I could be playing wrong.I have rather small hands and it is too hard for me to form certain chord shapes without messing up the sound. Is it possible that my hand is too small to play or are there like certain hand stretches that I could do? I need some help Please! 
I do that too. You can try using a capo. Different guitars have different necks, you just need one that fits your hands. Try going to a guitar shop and try out different necks and ask for help. You could also post on some instrument sites like HarmonyCentral and ask about smaller necked guitars.
Good luck.