I 'ride' the test on the ground to remember it, ahah like, without a horse, just make some little paper letter and set them up in your house or yard and pretend your ridng a test! Haha
Don't be nervous! The worst thing that could happen is you fall off, and that could happen at home too, so just stay calm and your horse should stay calm and it should go well!
Good luck! And don't be nervous! Showing is fun! :)