I know what homeschooling's like and I think it's cool that you're willing to start learning now.
Maybe you could animate plants growing?

Or try designing an animated Logo/intro ( like the Universal Studio's globe, 20th century fox logo, Pixar logo) of a seed growing into a tree then you pan out to show your company name like "The Sapling".
Only needs to be about 20 seconds long. And if you've ever done anything in film ( NTSC being 30 frames per second and PAL 25 fps) that adds up to about anything from 3weeks to 2months of work. Depends on how perfectionistic you are.
If you think it's a dumb idea that's fine. You will find out some day that animators are quite nutty.
The best advice I can give you is never stop looking. What?! Yes, looking. Also keep doodling and scetching, whatever, whenever. Because if you understand how things work and what they really look like, it's so much easier to do them in 3D.
See if you can redo the adverts on TV. Build your room in Maya. nothing needs to move, but see if you can do it.
Last but not least. Don't take yourself too seriously! Animating can get you seriously tensed up. Take breaks even when you don't feel like it. Don't be afraid to ask for help when you're stuck.
And do incremental saves.
Keep it up! And have Fun :-)
Z