In the grocery store, I would probably say "Where would I find beer?", not "Where can I find beer?" or "Where do I find beer?".
True dat. I'm an American midwesterner, though, and we are just overly polite sometimes. I think "would" and "could" get used a lot because of that. It's a more passive thing for us.
I grew up in the midwest and live in the south where people are overly polite, and all three of your examples seem pretty common.
I know you can't translate Russian to English literally but could anyone explain this structure and use of "мне найти"?
The pop-up over мне gave "I am", so I translated it literally as "Where am I to find beer?" Duo counted me wrong though, and I admit that sounds pretty awkward in English. Further to this question, could I say in Russian, Где я могу найти пиво?
I think that could be possible, but I think the use of «мне» here is related to the fact that «найти» is a perfective verb, and can only be conjugated to future or past tense and not present -- hence the use of мне + infinitive so that it can be used in present tense.
«находить», the imperfective 'find' verb, which does have a present tense conjugation, cannot be used here, as this expression is not concerned with the process of the action, but simply the outcome of the action of finding beer. See https://en.wikibooks.org/wiki/Russian/Verbal_Aspect
...What does the use of the dative case here with мне have to do with the tense and aspect of verb? That seems nonsensical to me.
Perfective aspect verbs have no present tense conjugation, only future and past. Thus, мне has to be used with perfective infinitive in present tense to make it grammatically correct (i.e. Я найти sounds very strange).
I just asked a real linguist what's going on here. He described it as "flavourful native talk;" it's not technically correct, but "everyone says it like that." That's comforting.
You can see it as the "где мне можно найти пиво?" ("where is it possible for me to find beer?") with the word "можно" omited.
(As a side note, you are probably more familiar with the word "можно" as "allowed", but it can mean "possible" too.)