OK just a short story from me, I enjoyed it from the moment I sat there in that left seat flying a heavy jet with 5 other students and 2 captains.
Offcourse you need to give a performance that you are capable, but if you did a good job in the sim then it's no big deal. Don't worry too much, a little should be enough to get your performance up there where you need it to be
Again like said, big boss will watch you when you handle your jet.
Beeing nervous and beeing aprehensive is natural.
I had a great day for base training with great guys and we all took pics and footage from the training.
Just relax, get some good sleep and enjoy the session.