Where can I train to be a smoke and fire eater?

There is not a large number of fire eaters. There are several websites where you can gain beginner advice on becoming a fire eater. Also you can check with your local carnival/circus and learn from others in the profession.

If you are serious about being a fire and smoke eater, you can apply to the Coney Island Sideshow School. The school offers various 'alternative' skills often used in circuses. Fire eating is actually a first level course, so you will get to jump right in. Once graduated, you get a degree and can go on to find many wild jobs that will take you wild places.