Internship

Next quarter will be my last quarter of school.
I found out that I will be able to take the last class where we will do sculpted cakes and wedding cakes.
As well as that final class I will need to have an internship. For the first time during all of this I am scared of failing. It has always been that even if I messed up I could pick up and fix it, but with an internship I have to have one which means I have to be confidant in my work enough to get the internship and do my job paid or not. But like finding any job it is nerve racking.
I have an application for a paid position at a chocolate shop and I have exchanged emails with the owner of a cupcake shop. I am nervous about doing the 3-4 hours of the working interviews. Any tips or advice??