If you have never shown in France before and have no contacts, then finding your first show will be difficult - even more difficult than showing your work in London if you don't speak good French.
The question of what makes an artist 'professional' is often debated. While professionalism in relation to arts practice is a lot to do with attitude and approach, there are certain basic resources you can develop to operate in a professional manner and help you develop your career.
You might find it useful to join a studio group so as to build your network and put on a group show. Most studio groups have a notice board with opportunities, and members can pool their resources and put on group shows, taking advantage of each other's contacts and networks.
A curator is most often an arts professional with a background in the visual arts, either attached to a gallery or operating on a freelance basis working with different private, public or independent spaces.