I'm applying too but as far as I'm aware you can apply from anywhere (in or outside Canada) as long as you meet the point system and you're area of training allows you to score at least 6 points. Then, you just need to submit your application to you regional visa office.
As for myself, I'm applying from outside Canada
On regards to your question about French, you can certainly enroll in a french course while you're applying - I guess it will help in the interview-. However, you won't get any points if you don't submit your certificates.