No. Free speech means all ideas (that are not themselves illegal) are free to be expressed. Especially if you disagree with them.

Rather than censor anything you don't like - people must learn to differentiate between what is true and what are lies, for themselves. Critical thinking skills. Verifiable proof.

Marxism is a failed ideology. It has failed catastrophically every single time it has ever been put into practice. Those facts alone should be enough to discredit that ideology for the vast majority of people.