I live in Canada and someone told me it was like 20 bucks to sue someone. Is this true?

Lawyers if you have any hope to win are much, MUCH more expensive however.

What if you just represented yourself? I know it's not recommended but is it a possibility?

I see that this is in the small claims section. Are you planning to sue through small claims court?

The cost will depend on where you live. You'll need to call and find out the cost to file in your area.