Any ideas on how to decorate my amazing cake?

K so im 14 and i am making a cake for a school project and i have no clue what im doing! lol the base of my cake is just gonna be 4 layers stacked on top of each other, like a wedding cake. And i want to have it bright green with pink little decorations everywhere. That is the main image i have in my mind but I dont really have much. Its definatly gonna b a girly cake, so could u help be brainstorm themes for my cake or little decorating advice. Im open to new ideas and could certainly change my idea if i found something i liked better. plz show a photo of some sort to show what u mean, ha ha im like a 3 year old.. i relie on picture books. k anyway THANKS SOO MUCH HOMIES!! LOL