A key thing to remember is that with languages it's impossible to cram everything you know in one go because it's a long process of building up your knowledge of vocabulary and grammar in order to give you the best chance to express yourself both in writing and orally. I recommend looking at news websites such as Le Monde to have a better knowledge of how sentences are constructed or reading more fun articles on French Buzzfeed to learn new vocabulary as you never know what may come up!
Closer to the exam, it's about knowing the subjects that may come up and knowing the key vocabulary for the topics as well as the key controversial issues and both sides of the argument. Listening to French radio or news can only ever help you!