I didn't watch the video, but just wanted to comment:
Why do you need to beat 'fancy' horses? Does a ribbon REALLY matter that much?
I compete for my own self satisfaction, if my horse behaves, stays on my aids and does a good job, then I am happy - whether I came first or last ;)
You're only 13, you have years to go. Right now, you should be mucking around, hooning around on your horse having a great time and not worrying about ribbons and beating other horses. We don't ride for ribbons, we ride for the enjoyment we get from being with our horses, and the satisfaction of their progress due to our training.
Eventually you will be up there with those 'big fancy horses'. But don't stress yourself out of it, you have PLENTY of time! At 13, I was still bashing around on a fat little welshie that bucked me off on a regular basis, always came last, and heaven forbid I enter an ODE on her - every single jump she would clear, then bolt and stop dead. I'd go flying over her head and eat dirt, get eliminated, get back on, jump, fall off, get back on, jump, fall off.... and you know what? I'd finish at the end, with a huge grin on my face, covered in mud and bruises, wanting to go back and do it again!!!! Yep, the older girls had their beautiful, sleek, well trained thoroughbreds and parents who bought them everything, but they would get off at the end of the competition, a scowl on their face, tie their puffing horse to the float, and go off to talk to their friends.
And now? Most of those girls have given up riding, and the ones who are still in it, I have beaten by a significant margin at nearly every competition we have attended. I saved my pennies, bought myself my own 'big, flashy horse' and have put in the hard yards to get there.
So smile, have fun with your horse, and enjoy being a kid!