Request #281 From Claire

I am looking for a book that I read approximately around 2014. I believe it had a green and purple cover. it may have had the word “soda pop” and a cup or a can on it?  the narrator is a chubby boy in high school who plays an instrument (i believe trombone) in the marching band. the marching band gets funding from the vending machine, but the school for some reason redirects it to the cheerleading team. the plot is the main characters trying to get funding back for the band. there is a love interest who works in a donut shop.