What's the difference between "What kinds of forest Canada has?" and "What kinds of forest does Canada have?"
Well, that's an easy question to answer - the first sentence is wrong and the second is right.
I don't know who taught you to say "What kinds of forests Canada has?', but they need to take some elementary grammar lessons:
The standard word order for questions is this:
1. Question word phrase ----> What kind of forests
2. Auxiliary or modal verb ---> does
3. Subject ----> Canada
4. Main verb ---> have
'What kind of forests does Canada have?' is the correct way to ask this question.
I hope that helps.