Just to give you a general idea.
1. Renting a place. In your case I would count 2 bedroom apartment / basement. You might try to get 1 bedroom one, but it might be a bit difficult, since you are a family of 3. From there on it would depend on which area you want. But it would be somewhere beween 1300-2000 CAD / months + app. 100 for electricity. You might try to rent a house, but that would be just more expensive.
2. Food. This can be anywhere from 300 per month to 1000+ per month for the whole family
3. Car or commuting - app. 300-400 per month and person (excluding the baby for now)
4. other expenses (Huggies, phone, internet, clothing) - 150-200 per person including your baby
So I would round it to app. 3000 CAD for the whole family per month.
And yes you can go a bit lower, but in a long term you cannot hold some expenses forever. And of course if you want more then it will be more expensive.
That is before you can actually save anything for unexpected big expenses.