Honestly, it's sounding like you're not wanting this job from what you've said about finding it hard enough doing the basics. I used to work at Greggs as a team member and honestly, doing the basics was difficult enough without having to balance things such as keyholding and even potentially counting the money at the end of every day or doing stock etc (if that's what's included in the senior team member, not sure!). If you really think you're going to struggle and that you already experienced issues at the shop before, why would you want to go back and work there? I'd suggest trying to find something else that you can do, or at least find a job at a different shop. I understand how difficult it is to find a job at the moment though so, if it's a matter of money, then I would understand why you may go for it. Really think about it and consider if it's the right move for you.