Let me know via private message if these are of any use to you! Im guessing this is for a flickr account or similar? You can check out mine if you want at Flickr: GFry Photography [on holiday]'s Photostream not many horse pics on there but hopefully you will find something you like :)
What you'll need to do - when you get serious into this and start a business, is that you'll have to buy your business name. So you'll write down 3 names that you like, and the government will tell you whether they are taken or not, and then go from there.
You're 13 or 14, right? I don't think your photography needs a name. Naming it might cause problems later. Think about it....you have changed your horse's name so if you name your photography now you might change your mind later. Please realize that I'm not trying to be mean at all. I can tell you that I certainly am not doing what I thought I'd do at your age. Times change. We change.