Everyone will seem much more qualified than you are. They will also seem far more friendly, more expressive, more capable than you. Take a deep breath. You’re here too.
People will genuinely be amazing, kind, talented, funny, etc. They will also be just as nervous as you are. Lean into both of these things. Nerves are okay. Sharing funny stories is also (more than) okay.
You will question everything you say post-interview. This is normal. Just try not to do that during the interview, okay? You will end up forgetting what the person in front of you is asking.
It will be extremely hard to judge your performance, particularly after your first interview. Breathe. Don’t ruminate.
After allowing yourself to ruminate (it is ultimately inevitable), remind yourself kindly of what you are trying to achieve. Your goals, your individuality, your worth do not depend on an outcome.
Carry on. Talk to friends. Not about the stuff covered within your theoretical NDA, but about everything and anything else.
Be proud that you made it this far. Every experience in life is worthwhile.