I am writing this in assumption that you are not familiar with canoes, if you are I apologize.
I would suggest that you camp at a lake where you have close access to the water and beaches, preferably a smaller lake where the winds will not create a problem with rough water.
Take a couple of hours at a time at the most and spend paddling around, get used to the feel of different loads in the canoe, such as kids and adult combos, including letting the kids splash their hands in the water, if they are old enough, let them help paddle, or even let them play around near shore with supervision on their own.
It could be a long day if you get a couple of hours of paddling away from your camp and have decided it is not for you, then you have to paddle back for the next two hours, weather changes and you end up on a beach miles from your camp.
If you have previous experience with paddling, then go for it with the previous suggestions. Also, make sure you have life jackets for all in the canoes.