I'm 22, I bought my place at 18. This is what I did: I bought a 3 bedroom triplex unit with 5% down. This means paying extra through CMHC every month because it is seen as risky. The place I bought was only $100,000 (East Coast of Canada) and was in walking distance to the University I was going to. I then lived in it and paid "rent" and had two roommates who also paid rent.

This has allowed me to share the down payment with other people (they are just renters) and I've been paying the same as I would have if I had rented. Only I'm working down my mortgage and getting some appreciation from the property which when I sell to upgrade properties will give me a nice down payment for the new property. I have also learned a crapload that they can't teach you in school.

What I did to get a down payment was worked my ass off in Calgary for a summer and then used the savings for a down payment.

Feel free to PM me if you have any questions.

Good luck.