Hi
Once someone has become a Canadian Citizen they can have two passports, one UK, the other Canadian.
Dual citizenship is allowed.
Driving licenses can be exchanged, but I do not believe that passports get swapped.
I think that you would have to relinquish citizenship of the UK (or let your UK passport expire) if you only wanted a Canadian one.
Both Canada and the UK recognize dual citizenship, so once you become a Canadian citizen, you don't lose your UK citizenship, nor do you surrender your passport.