I'm going to call a fellow student kiddo
What is making you want to call another student kiddo?
He is much larger than me so it is my way to feel better. He also has acne.
You shouldn't call another student kiddo just because of their acne and height. If you are calling them this name just to be rude and disrespectful then you should analyze why you have the urge to do something like this.
If I'm being rude, so what? He's a little shit even though I am taller than him.
You should avoid being condescending to other students. Try to focus on getting to know people for who they are. This may help you to stop judging people based on their appearence.