Starting a job at Greggs

From what I know, all personal belongings need to go into a locker. The thing is, I always carry a pretty big rucksack everywhere with me and I won't be surprised if it doesn't fit in a locker. I do have a couple smaller bags but I don't like carrying them because I can only fit a few things in them and my papers (that I need to take on my first shift) will probably get crumpled. Would I be able to take my big rucksack with me but put it in a different area of the store? Or should I just bring a smaller rucksack that would probably fit in my locker?
I would call the store myself but they're closed.
Btw, I am not planning on bringing anything too valuable, so security is not a problem
Thank you!

Your overthinking things lol. Of course you can take it and just leave in the staff room or office or something.