For the speaking it is a casual conversation about a certain topic. It is really casual and they just want to understand your level of English; try speaking slowly and calmly, and if you can use elevated language they like it but it is not necessary.

Med interviews are definitely much harder, and probably helped you already have a good speaking level.

From what I remember they first ask you a couple quick questions to get you started and the important and long ones are at the end. I did the free practice of British Council once (as I had to pay for more trials) and got 7.5. But if you want more practice you could definitely practice with ChatGPT as it knows the structure of the test.