Business Studies is the 3rd most valuable GCSE you could get imo.(after English and Maths because they're the basics that everyone wants)
Business Studies gives you the knowledge and mindset you need to work in an actual business and manage your own finances. It also gives you some of the knowledge you need to start your own business if you want to go that route, so you have better prospects than most uni students.
If you did well in French, then you're at least almost bilingual. Every employer and university loves being able to tick off that they've got bilingual employees/students, because then you can represent them in two different languages.