Hi, ArtVandelay!
Great to hear about you willing to improve the diet.
First of all you need to ask yourself : what do I want to get from improving my diet ? Simple 'WHY ' needs to be asked if you want to take some steps.
See...it is very good you are thinking about getting rid of processed foods.But, it is a first step only, and for some of us it is a big one ( if we eat mostly processed food ), for others small ( if they have a goal to dramatically improve the health ).
However you would look as 'processed foods' it is a food that was altered , meaning : cooked, broiled, compound with additives.
If by 'getting rid of processed' means no coca-cola and burgers from fast food at school - it is a small step, but necessary one.
We don't know what have you been eating, so I am assuming : pop tarts for breakfast, pepsi, pizza or something like such.
But almost every packaged food is processed.
So-let us know what is your diet ?
Simply don't eat schools meals, prepare your own ( and we can discus what you'd be willing to eat that would be made by you).
Also - high school girl ( you lucky one! )- you have to be at pretty good health to begin with, because you are young! I am not saying that all young people are healthy, but that results of our lifestyle/diet can come to the surface after sometime of abusing the body.
It all depends.
Meat is highly addictive, that's why you like it;-)
Also - you don't really like meat, but all the altered state of meat ( cooked, fried, seasoned ).
Wish you all the best and tell us more about what you eat and how committed to making health changes are you.!