You need to know this is what you want before you go putting yourself through a fire academy and spend all that money. Try getting on with your local fire department as a reserve firefighter. Most departments are always looking for reserves because they basically work for free. This will give you a good look at what the job is all about. Plus, it will provide you with good training, and knowledge. If you are lucky, that department may even pay for you to go through the fire academy, or will hold a full-time position for when you complete it.
Best of luck to you.