To be honest I'm not even quite sure what you mean when you say "film stores". It could mean stores that sell photographic film, or stores that sell movies. Presumably you mean the former, but I certainly wouldn't call stores that sell film as "film stores". They'd most likely be photography stores or maybe at big box/department/pharmacies. In that respect, asking for "film stores" is like asking for "bacon stores".
I am not from the USA but I was going to respond to say I don't know if "film stores" have existed for decades, so searching for "photography store" or "camera store" would be far more appropriate... but sadly Yep fails at "photography store in los angeles" and for "camera store in los angeles" only gave one good result :(
