I was 15 in a car park at asda with my dad, I remember trying to catch the car on the clutch without knowing that your kind of supposed to stop first.
Its a good job I had a fair few runs as a friend let me have a go in his car in a fish shop car park at 17 and I ran over a girl we were with, it was totally her fault but my mate was glad I could drive, this was my first emergency stop, I didn't even stall the car.
Good luck with your driving!