Its very very difficult to get into show photography, believe me I've been trying! Its one thing to have friends buy from you, thats where I get most of my business from
but most shows already have a photographer well in there. I'm not a pushy enough person, you have to be extremely confident in your work, and I'm not happy charging the prices that the pros do, but that is how they get their money back. They have very very expensive kit, most of them have on site printing etc which is also in the thousands of pounds, you have to work in all weathers if you are booked, etc etc. Indoor showjumping etc needs a decent external flash which I know for my camera is about £300 which is why I haven't got one yet
Don't bank your life on it just yet, keep it as a hobby and make a little money off it, whilst getting qualified in something else to pay for it because it is a very expensive hobby. And its flooded with other people who are always just as good if not better and it can get a bit disheartening! And especially now, people are just not spending so much on luxuries, and photographs are a luxury. It also kind of dumbs down your enthusiasm when you are spending more time organising and perfecting and resizing and uploading pictures than you are actually taking pictures!