Hey Mariah, I'm in the process of writing a novel too.
Here are some things that are helping me, and might help you:
-Carry a little notebook around with you everywhere, and jot ideas down in it as they come.
-Pay attention to detail in real life (How the wind makes the trees sway, or how your best friend smiles, etc.) and then apply it to your story.
-Draw inspiration from other artists. (Listen to a CD, read a book, study a painting, watch a movie, etc.)
-Think about things in different ways. (Look at objects from new angles, close your eyes and imagine what the world would be like if cupcakes came to life and sang and danced in the streets, just don't think how you normally would.)
-Live. Life experience is one of the most important writing tools you can have.
Don't worry about being original or unoriginal. Just be you and worry about the editing later. Best of luck! I hope I helped a little bit.
Happy 16th, by the way!