Nerves, practically

Nerves are not evidence that you are underprepared and they do not disappear with seniority. They are manageable with mechanics: know your first two sentences by heart so the opening cannot stall, arrive early and stand in the actual room, deliberately slow the first minute because everybody speeds up, and allow yourself to pause — silence feels far longer to you than to the room.

Rehearse aloud, standing, at least twice. Reading through in your head is a different task and does not transfer. And if you are asked something you cannot answer, say so and offer to follow up. Audiences forgive that instantly and remember bluffing for a very long time.