Im going round a girls house for the first time

Im 16 (M) going round 16 (F) house tomorrow and sleeping over, but im scared my dick is gonna be too small and im gonna embarrass myself, for reference my dick hard is about the same size as an iphone 13 which is like 5.8 ive talked myself up to her so much i dont wanna disappoint her also please can someone give me advice on how to clean it