I completed my Level 3 IT Solutions Technician apprenticeship a couple of years ago, and I was also nervous, but it turned out to be good. The person I spoke to was very polite.
I'm assuming you will have been tasked with completing a portfolio of some sort over the duration of your course, to document any tasks or projects you've been involved in. In addition, you may have also completed a project under controlled conditions (I did for mine).
The professional discussion is honestly not as scary as it sounds. I had mine over a Microsoft Teams meeting. The person on the other end would have my portfolio to hand, and I would also have a printed copy for easy reference. I would then be asked questions or be prompted to talk about some of the tasks that I'd documented on my portfolio.
Assuming it's following the same criteria as mine, the person you have the discussion with is going to be looking for three things in particular for each task you discuss.
-What (What you have shown you can do)
- How (The way in which the work has been done)
- With Whom (Did you work alone, or as part of a team. How did you work effectively as a team or alone?)
Don't be afraid to go into technical detail, but if you want to go for the Distinction, they're essentially looking for you to identify all three of the bits above (The What, How and With Whom).
They will ask you some questions as you discuss each task or area, which are designed to help you out and enable you to deliver the information the best you can.
Best of luck to you!