They'll LOVE you Lexi so don't worry about that!
As for resisting fatty or sugary foods tonight... how do you want to feel tomorrow? Do you want to be energetic after a good night's sleep fuelled by high quality nutrients or do you want to be crashing from a sugar high and dealing with a breakout of pimples for too much oily or sugary food?
Eat some healthy snacks and you'll feel miles better tomorrow.
I know you'll do brilliantly! Just try to relax and show your true wonderful self to them.