best thing is just try and relax and pay attention during the test. Your english seems pretty decent and its really a test to see if you can understand english and use english in other settings.
When i did mine a couple years back it included:
- Explaining words/phrases
- Listening to recordings of conversations in different accents and explain what was going on
- Explain a picture
- Pick items from a list and explain why you chose them
- Watch a short video and explain what happened etc.
The hardest bit is probably listening to the recordings as the accents can be quite strong so you will have to pay close attention to what is being said.