How can I improve my accent?
Really go for it - it may sound silly but imagine that you are French and feel confident when speaking. Try and talk as much as you can - have a conversation with yourself! This will also help your vocabulary and your grammar.
Another option is to immerse yourself in French audio. Listen to the radio, listen to songs, watch French films etc.
EG
Related French GCSE answers
All answers ▸How does one distinguish between the perfect tense (passé composé) and the imperfect tense (imparfait)?
How do you know when to use the imperfect tense and when to use the perfect?
How can I learn new vocabulary more easily?
How would you say "I enjoy being with my friends. When I can't see them, we keep contact by text message" in French ?