Hanna, there are websites dedicated to improving hearing words. This improves fluency if you also try and copy the pronunciation. Then you can work with a tutor who can help you improve conversation - correcting you as you make mistakes, and helping you to say what you want to say. This will always work the best - especially if they help you with your confidence as well.
Watch movies and try and copy the sentences sometimes. Learn 5 new words every day.
Those are the basic tips.