What is it about grocery stores/super markets/corner shops etc that make new expats freak out? I'll tell you my theory: Most expats are actually wanting a reason to freak out and food shopping is usually one of the first chances they get.
Let me explain... Most people in England have a store of some kind that sells food (call it what you wish) within walking distance from their home, so when a new expat can't yet drive and is left on their own for the first time, they brave a walk to the shop. They walk in cautiously, look around nervously, pace the aisles looking for familiar items and become quickly unnerved when they notice they shelves are full of jars, boxes and packages of things they've never seen before. If they do make a purchase, they muffle their speech as if anyone will care they have an accent and experience further angst when the person at the till (cash register) doesn't bag their items for them. Then it seems many of these new expats run home to their comfortable computers and their virtual community of other expats and inform them all they have just been brought to tears by a trip to the grocery store. Yes, seriously. Don't believe me? Send me a message.
And about that second part of my theory? Why would any new expat want a reason to freak out? For attention, of course! If you don't have your first "isn't it silly what made me freak out" freak out, all the other expats and your family and friends back home cant mollycoddle you, remind you how brave you are for moving so far away (as if you've the only one who's done it) and marvel at how "weird" things are here. Duh!
My unsolicited advice: Don't think you're brave by going to the store - you aren't and it will just build it up to be something scary causing the above chain reaction. Watch what other people do if you aren't sure of something. Most stores in England will not give you bags unless you ask for them and very few will bag your groceries for you. Ask for a bag (don't be surprised if you are charged for it), bag your groceries like a big girl or boy and be excited about the cool new things you may have just purchased. I suggest Prawn Cocktail Pringles.