There is no requirement whatsoever if you already have Canadian citizenship as Canadian provinces have unrestricted migration.

But foreing immigrant applicants get bonus selection if they speak French and apply in Québec.

The most relevant limits to help preserve our language : large companies have to function in French ( with a bunch of exceptions rendering the law barely applied ), and companies must offer their services in French ( and whatever language else is allowed, but French must be there. )

Public education is mandatory in French before college ( with mandatory English second language classes ), unless you have special right to public English education ( from your parent(s) ) in something called the "Clause Canada", so English speakers from Canada qualify, but not immigrant from outside Canada, even if English is their mother tongue.

Private education can use whatever medium language of instruction and there are many English schools.

The federal government also use disproportionate amounts of public funds to ensure English language services in sectors such as healthcare even in regions with less than 5% English speakers. This is rarely reciprocated for such small French minorities outside Quebec.

Public services / documents from the Québec government are fully avaliable in English ( including laws / court proceedings ).

Cities and villages usually conduct their activities in French. Some with many English speakers are de-facto, or officially bilingual and provide services in both.

Native American and Inuit towns are free to implement their own services, education and media in their native language ( and many do it, at least for elementary schools ). They even recieve large subsidies to do so.

The sheer volume of immigrants/"refugees" has overwhelmed all integration efforts, especially given the low fertility and low social prestige of the the French, and our language is quickly falling behind.