Don't worry, I had exactly the same questions
When the applications are in, they shortlist the ones they want to take further. In my case, I got shortlisted and a week or two later the manager rang me and gave me a really short phone interview. He just asked a few questions about my experience and stuff, nothing tough. We then organised a date for the induction (which you get paid for by the way) two weeks later. From what I remember, it only took about an hour or so. We gave them our birth certificates and stuff so they could photocopy and then we watched a couple of videos. One on 'what if someone tries to bomb the store!' and the other on general sales policies and stuff, and how things run during the sales. We then got taken on a short tour, first to the main stockroom where we could learn how to clock in and out. We all had a go at that and we got the information of our first shifts then too, so when and which department. We also got our payroll numbers then. Then they showed us how to use the little tagging machines in case we were put on repricing items on one of our shifts. After that, they took us down to the shop floor and showed us where things were, and showed us how to sign in/out. After that all we had to do was pick up our things back at the office upstairs then sign out, and we were good to go. Then all we had to do was turn up for our first shift, whenever that was
As for working there, if you're on the shop floor you'll most likely be tidying up and helping customers until they've till trained you, and then you'll do a bit of both. You'll be assigned a department, so you won't have the whole shop to deal with! You may also be put as front of house, in which case you'll be stood by the doors greeting people and offering bags. The night before the sale, pretty much everyone will be in until late bringing stock to the shop floor, rearranging everything, and pricing/tagging ready for the sale to start in the early hours of the next morning. When it comes to sale time, you will be tidying a lot. The dressing rooms will be closed so no one will be working that. It's mainly gonna be tidying, offering bags, and till work. It's very fast paced, but I always liked working on the tills
I hope this helped! Let me know if you have any more questions