Is that "store" in the American sense of "shop"? Or does it just mean "store" as in "Storeroom"?
I looked this up - it definitely means shop and I can't find any suggestion that it means storeroom - I think they must just mean the American usage of store
Yes, "Laden" means shop. The German for storeroom is "Lager". Fun fact: Lager beer is called that because it can be stored over a long period of time.
You sometimes use German "in" and in other cases "im" for the English "in". What is the rule of determining which of them is correct in the particular situation?