Starting from scratch, you would need to be something like 7 years old, thats when most racers like Lewis Hamilton and Michael Schumacher started in Karts.
To start racing at your age, i suggest getting a car and doing some trackdays at a local track or something. I'm sure you can get a runner for under $500 Canada Money.
Something you haven't specified is what kind of racing you want to do? Track racing, Autocross ect. This question will set you up for what i'm going to say next.
If you seriously want to get into racing, the cheapest would be autocross i guess. You need a car, saftey gear and an event to register for. Google for local events and entry costs.
If you want to get into track racing with others, this is where it gets more costly. Any car should do for a track race, for example. A car that you can buy for $500, you will eventually need to pour money into it to make it track safe and to conform with the rules. On top of that, there is cost for saftey gear, spare parts, event registration and insurance. Again, Google will provide more info than i just posted.
The same again goes for Rally Racing too. A good thing to read about Rallying is How a $500 Car Beat $400,000 Rally Racers. Even though he bought a car for $500, it still cost mounds to prep it and register in the event. And i will mention again, Google should provide all info for this type of racing.
In the end, most of the drivers in top flight motorsport have actually come from a family of racers who get their kinds in at an early age, aswell as pour money into their careers. Hope i have help you in what you decide to do. I think this is only the basics of trying to get into motorsport.
My personal advice though. Quit smoking and go to the local Kart track.