Most French people understand some English.
But I wouldn't say they are fluent.
Let's say they can get by.
Sometimes they won't talk to you in English because they don't feel comfortable enough with the language...even if they understood your question, they might not know how to answer it properly.
French kids have to learn at least two foreign languages in junior high/ high school.
Most of them do learn English.
However, the first two years of junior high, you only pick one language, and then you take a second language after these two years.
So people who pick English as their first language are usually better at it than the ones who chose it as their second language.
But still, the level of fluency depends on whether you're a good student or not. Mostly nowadays with overcrowded classrooms.