Does Canada have free speech rights
Yes, it's in the charter of rights, which is part of the constitution.
Trudeau supposedly addressed that today: “We are not limiting people’s freedom of speech. We are not limiting freedom of peaceful assembly. We are not preventing people from exercising their right to protest legally. We are reinforcing the principles, values and institutions that keep all Canadians free."
To put this whole thing in perspective, the last time these powers were used was after the FLQ detonated hundreds of bombs over some years, kidnapped a politician and held him hostage, tried to blow up a bank branch using a car with 100 lbs of dynamite, etc. There were real dangers to tackle very quickly, the military was protecting politicians, etc. This pales in comparison to that crisis.
Trudeau wants to use these powers to seize these truckers' personal and corporate bank accounts, have their insurance cancelled, etc.