How do I make this costume?

Ok this is going to sound a bit weird, but I am going to dress up as Tesco for a dressup party I am going to. It’s a long story but basicly its an inside joke between me and the host about Tesco, and I have also been given the letter T as my costume theme. So how would I go about dressing up as a Tesco? I had an idea that I could use a large box and use something like suspenders to keep it on, but I don’t know how I would make it look like a shop
Thanks