Read. A lot. Read like crazy. There are a tonne of reading materials. Read essays, keep a notebook, and copy key phrases or things you like. Do this every day. For speaking, find sentence drills, or make them. Just drill sentences you find in books. Read a lot of fiction with a high content of dialogue. Modern plays are also really good for this. Find scripts of your favourite TV shows and read through them and say phrases OUT LOUD, because spoken words are muscle memory. To speak confidently, aim to master getting angry. Using a foreign language under pressure is really hard. Listen to podcasts on half speed, repeat phrases when you feel like it. This will help rapid speech, chunking of information, and idiomatic expressions.