I have worked at tescos for 18 months and I applied for checkout work. I was also offered 'aisle 1:cheese and butter replenishment' but that didn't really take my fancy.. thought it'd be cold and not quite the hip thing to do working stacking shelves. the job was great to begin with, easy money sitting on your bum all day, but it gets extremely tedious and boring. you can work on shop floor, deli, the bakery, dot com, customer services, kiosk, photo desk and in bigger stores i;m sure there's much more you can do, but you can also train in more than one area (if they ever get round to training u!)
as far as i know tescos doesn't pay minimum wage because I thought minimum wage was £3 something. At age 16 I started on £4.20, you then get a rise after 6months to around £4.50 and a rise again when you're 18 and when you have been working there for a year. Different departments also pay slightly different I think.
As for getting the job.. depends how much work is going but the interview isn't particularly strict just make yourself sound reliable and outgoing and make out that you have some customer experience and you should be fine. However don;t aim for tescos as a long term career prospect.. you will get extremely bored! hope this has helped in some way x