USA: Spanish. I’m learning Spanish, and I think as a whole it’s like 18% of people in the USA but I feel like you’re likely to encounter some Spanish speakers and make friends even if not everyone speaks Spanish here.
Brazil: It looks like Spanish is also the second most spoken language with 4% or English with around 5%. I’m sure you’re more likely to find people on the Internet who speak it.
French: English, apparently a quarter of the population speak it??? Not sure how likely you are to find someone in the wild speaking it, but on the Internet, a lot of people.
I live in Canada, where official languages are English and (Québécois) French, so yes, you could make many friends. I think about 1/5 of Canada is effectively bilingual, but there are also a lot of people who speak French only.